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Go to Editorial ManagerIn this paper induction motor and its direct torque control are simulated and a speed estimator scheme based on wavenet (WN) theory has been developed and compared with the actual speed. The wavenet speed estimator inputs are a single line current and the state of the torque comparator output which are trained to follow the relationship between the motor current and the rotor speed. To ensure the validity of this scheme, the estimated speed is compared with a speed estimated from a conventional model reference adaptive system (MRAS). The operation of direct torque control (DTC) drive with the actual speed and the estimated wavenet speed as a feedback signal are simulated and compared. The results show that the wavenet method is effective for rotor speed estimation.
In this paper friction stir welding process has been studied whereby utilized FEM method (Ansys software ver. 20). The main effective parameter in this process were rotational speed, linear speed, tool shoulder radius, heat transfer coefficient and clamping percentage to study their influence on represent temperature, von misses stress and frictional stress distribution. Because of the difficulty to obtained the number of the simulation cases in order to get the most important results, Taguchi L27 orthogonal array was apply to reduce the total number of the simulation cases. Pure copper (t = 3.18 mm) material type was applied as work plate material. ANOVA statistical tool was utilized to achieved the optimization process after the simulation cases done. Percentage of contribution of each parameter can be obtained by ANOVA table and mean of S/N ratio plot. Validation process was achieved between the Current study and experiment work in the temperature distribution field with percentage of error 2.7 %. From optimization result It is found that the optimum condition in order to obtained good results for temperature was rotational speed of (450 rpm), linear speed (2.75 mm/s), tool shoulder radius (7 mm), heat transfer coefficient (300 w/m 2 K), clamping distance percentage (40 %). And for von misses stress was rotational speed of (550 rpm), linear speed (3 mm/s), tool shoulder radius (7 mm), heat transfer coefficient (300 w/m 2 K), clamping distance percentage (20 %). While for frictional stress was rotational speed of (450 rpm), linear speed (2.5 mm/s), tool shoulder radius (7 mm), heat transfer coefficient (300 w/m 2 K), clamping distance percentage (30 %).
An intelligent and anticipatory speed controller for internal combustion engines was designed theoretically and examined experimentally. This design was based on the addition of a torque loop to the main speed loop. The model can sense the external load with the help of a load cell and send this signal to a soft computing unit for analysis and processing. This scheme will improve the ability of anticipation of controller since it treats the factors that affect the speed, not the speed itself. The experimental design was implemented using two types of actuating techniques; an intelligent throttling actuator and an intelligent injection actuator. The signal was analyzed by using intelligent techniques such as fuzzy logic, neural network and genetic algorithm. The experimental data were used to train the neural and the Adaptive Neuro–Fuzzy Inference System. The comparison of the results obtained in this work with other available models proved the efficiency and the robustness of the present model.
Friction stir processing is a new method of changing the properties of a metal through intense, localized plastic deformation ,this process mixes the material without changing the phase (by melting or otherwise) and creates a microstructure with fine, equiaxedgrains, It is used to improve the microstructural properties of metals. In this paper, the enhancement of mechanical propertiesof friction stir welding specimens at variable rotation speeds (1100, 1300 and 1500 rpm) with constant feed speed (60mm/min) for 6061-T6 aluminum alloy is studied by using the friction stir processing method at the same variable rotation speed and feed speed in order to transform a heterogeneous microstructure to a more homogeneous, refined microstructure. The best results of the welding line at the parameter 60 mm/min weld speed and 1300RPM rotation speed for the friction stir welding (FSW) and friction stir processing (FSP) where the efficiency reaches to 84.61% for FSW and 89.05% for FSP of the ultimate tensile strength of the parent metal.
This study uses intelligent techniques to regulate brushless direct current speed (BLDC) motors. After these motors solved the problem of using brushes and commutators in traditional DC motors, they succeeded in replacing brushes and commutators with electronic commutators. Due to the use of electronic switching, brushless motor algorithms are more complex than those of conventional motors. In this study, to adjust the PID controller's settings (Kp, Ki, and Kd), a trial-and-error approach was taken, and a completely new method known as the settings of known PID controllers have been modified using the new Gray Wolf algorithm. A BLDC motor's main benefit is that it has easy speed adjustment across a broad range, whereas AC motors often cannot be controlled in this way. Through the use of Matlab/Simulink, the BLDC motor's mathematical model was developed and implemented. The simulation results show that in the first case, a PID controller effectively induces the turbulent dynamic behavior of BLDC under load and no-load conditions, and in the second case, the speed shows the lowest rise time, stability, overshoot, and stability conditions, and performs at its best. The characteristics of the traditional PID controller that regulates the engine speed must be regulated online to achieve the use of intelligent technologies, and the adjustment is done online using the neural network. The results showed that this technology, or feature - online tuning - is the most effective and reliable of all.
A mathematical model to analysis three–dimensional forced convection turbulent flow in a novel solar air heater integrated with multiple rectangular capsules filled by paraffin wax-based on phase change material PCM was implemented. The investigations were performed under three airflow speed of (0.6, 1.2, and 1.8) kg/min and average solar flux of 625 W/m 2 . The results revealed that the delaying melting time and also lower the melting temperature of PCM by increasing airflow speed during the charging process. As well as, the freezing period is dependent on the airflow speed by inverse relation. Also, the data results represent that the useful energy rate and thermal storage efficiency were a strong dependence on the airflow speed. Moreover, it can be detected that the optimal freezing time and the air temperature rise of the heater were reached about 210 minutes with (12 – 1.5 °C), 150 minutes with (7.5 – 1.4°C), and 120 minutes with (5.5 – 1.5 °C), at airflow speed of 0.6, 1.2, and 1.8 kg/min, respectively, which can be used at night to supply some applications by thermal energy such as heating buildings and drying agricultural crops.
In this research work, the influence of cutting parameters and drill point angle on the temperature distribution in dry drilling of stainless steel AISI 304 was numerically investigated by using FE method based on DEFORM-3D V.11 commercial software. Two cutting tools of 10 mm diameter but different in point angles, one is 110° and the other is 118°. These tools were imported from specific website in a format of STL and inserted in the program during modeling of cutting tools. The material of the cutting tools is selected as high-speed steel. The workpiece model is created as cylindrical shape with 50 mm diameter and 5 mm thickness. The cutting parameters are selected as three cutting speeds (100, 200, and 300) rpm, with three feed rates (0.15, 0.25, and 0.35) mm/rev. The depth of hole is fixed for all simulations (3 mm). The percentage of increase or decrease in the resulted temperature according to the various cutting parameter was also calculated and discussed. The best cutting performance of tools according to the change of point angles was also investigated. The results provided a significant influence of cutting speed and tool point angle on the temperature generated in the machined models and very small influence of feed speed on the workpiece temperature.
Vibration in rotating machines and structures is normally measured using accelerometers and other vibration sensors. For large machines and structures, the process of collecting vibration data is tedious and time-consuming due to the large number of points where vibration data must be measured. In this paper, a novel non-contact vibration measurement method has been introduced by using a high-speed camera as a vibration measurement device. This method has many advantages compared with the others. It has a low cost, easy to setup, and high automation. It also can be used for full-field measurement. Many tests have been accomplished to prove the validation of this method. The verification test has been accomplished by using the machinery faults simulator. It presented a reasonable validation that the operation deflection shapes (ODS) and the phase difference of any object can be successfully measured by using a high-speed camera. The mode shape tests have been accomplished by using the whirling of shaft apparatus device to extract the time domain, frequency domain, ODS, and phase differences for many points on the shaft at the first two critical speeds. The results proved that the high-speed camera can be used to detect the vibration signal in many different fault cases. It also proved that the high-speed camera can be used to detect the ODS and the phase angle difference. That gives the proposed method more robust and acceptance.
In this study a two dimensional, steady state propagation of the laminar premixed flame was numerically and experimental are investigated. The energy, momentum, continuity equations for species and global reaction mechanism with equation of stat for ideal gases were solved. Constant temperature boundary condition is applied on axi – symmetric in y – direction domain. The governing equations were discretized by using computation fluid dynamics (CFD) and finite-volume method - central differencing scheme, then solved using Gauss-Seidel Iteration method on uniformed grid with VISUAL BASIC code. Effects of equivalence ratio and initial temperature of fresh gases (air – fuel mixture) were investigated for three types of fuel Methane, Propane and Butane. Also the flame speed and flame temperature were experimentally measured for air – fuel (Methane, Propane, Butane and LPG) mixtures. The burning velocity was calculated depending on the flame speed and flame temperature measuring. The flame speed and flame temperature were measured by using optical technique. Effects of equivalence ratio and initial temperature of fresh gases (air – fuel mixtures) on flame speed and flame temperature are investigated experimentally. Results were generated for the detailed description of the local fluid flow and heat transfer characteristics including temperature, axial velocity, density and mole fractions profiles. For example the flame speed reached 274.4 cm/s as a maximum value at Ø=1.1 for propane air mixture, and flame temperature comparison give a good agreement between theoretical and experimental results at rich mixtyre
Monitoring the health of rotating machinery is essential to ensure system safety, achieve cost savings, and enhance overall reliability. The requirement for a reliable and clear method of identifying defects has prompted the development of several monitoring techniques. They utilize vibration, measurement of the motor's current signature, and acoustic emission data in the process of condition monitoring. The MFS (machinery fault simulator) equipment was used to determine bearing faults using vibration signal analysis. MFS conducts simulations and investigations of many bearing issues, including those occurring in the inner race, outer race, and balls. An accelerometer (type B & K 4366) was connected to a data acquisition device (IDAC-6C) to record vibration signals under different operating conditions. Furthermore, a tachometer equipped with an LCD display is employed to measure the rotational speed. Four types of defects in ball bearing (Koyo 1205C3 type) were studied, the slot in outer race with size 0.196 mm, the slot in inner race with size 0.191 mm, in ball with size 0.196 mm in additional to compound defect. In this paper, spectral correlation technique was employed to detect defects in ball bearings running at varying speed, along with spectral coherence and the corresponding Enhanced Envelope Spectrum (EES) in frequency-order domain and order-order domain. The results show that the adopted methods, that are used to analyze the real vibration signals for diagnosis the defected ball bearings, are suitable, accurate and less processing time for varying speed. The processing time of the FastACP method used to analyze the signals in order- order domain is less than that of the adopted method in the frequency-order domain for any defect type. Overall, using the FastACP method in the order-order domain significantly reduced processing time by approximately 27% compared to the adopted method in the frequency- order domain under varying speed conditions.
This study presents a speed control design for switched reluctance motor (SRM) drive based on PID controller. The applications of Switched Reluctance Motors (SRMs) have being increased day by day, but this type of motors represents a highly nonlinear system, therefore there are a lot of difficulties in modeling and controlling them. We have proposed a non-linear mathematical model of a four phases 8/6 poles SRM then simulated it through Simulink/Matlab facilities. The whole control mechanism consists of a hysteresis current controller to minimize the torque ripple and a PID speed controller. The control design results are then validated in real-time by Simulink/Matlab software package.
Surge pressure is the additional pressure created when pipes move downward, and swab pressure is the pressure reduction that occurs when pipes move upward. When pipes are raised, it can result in a decrease in the pressure at the bottom of the hole due to the influence of pressure. An investigation showed that surge pressure is important for the circulation loss problem produced by unstable processes in Management Pressure Drilling (MPD) actions. Trip margin is an increase of mud density for providing overbalance so as to recompense the swabbing effect through pulling out the pipes of hole. Through trip margin there is an increase in the hydrostatic pressure of mud that compensates for the reduction of bottom pressure due to stop pumping and/or swabbing effect while pulling pipe out of hole. This overview shows suggested mathematical/numerical models for simulating surge pressure problem inside the wellbore with adjustable cross-section parts. To run the analyzed models, input data such as fluid speed around the drill pipe, pipe movement speed, hole diameter, drill pipe diameter, and internal drill pipe diameter are required. These data can be obtained from the drilling rig website. Swab pressures and surge pressures have been the primary causes of wellbore instability and blowouts in the oil industry for many years, resulting in pressure changes. This review focused on the most important basic theories for calculating the optimal factors related to surge and swab pressures and then linking them to the most important programs for calculating them. One of the most important conclusions from this review is that the optimal speed must be determined for the lowering and raising of pipes, to prevent kick or losses.
The accurate prediction of machinery faults is considered an effective strategy to increase the operation life of machines, ensure smooth operation, and provide a safe environment. Accordingly, the demands on predictive tools such as machine learning to detect machinery faults before catastrophic failure occurs has increased rapidly. In this research, a diagnosis algorithm based on using a 2D color-coded map as the input to a deep artificial neural network is proposed. These maps are called RDEgram after the processing of vibrational signals based on reverse dispersion entropy (RDE) method. The effectiveness of the proposed algorithm is investigated by testing its capability to detect different faults located at different locations on ball bearings under constant speed conditions. First, the squared envelope signal is extracted by applying the short time Fourier transform to vibration signal. Then, the RDE is used to process the squared envelope to detect the range of frequencies at which the transients occur. The RDEgram color-coded map is used to represent the RDE values as a function of frequency and frequency resolution. The maps from different fault features are collected to form the diagnostic patterns. Finally, a pretrained convolutional neural network (CNN) is applied to learn the feature pattern and diagnose the bearing faults. The CNN is trained using fixed- speed data and then it is applied to diagnose faults in the test data recorded at the same speed. The prediction method adopted in the current research shows a 100% level of accuracy for predicting two types of faults (pit and slot) located at various positions a ball bearing (KOYO 1205 C3 type) running at two constant speeds (25 and 30 Hz).
A five-phase two-motor drive system with a series connection of stator windings and decoupled dynamic control is considered in the present paper. The two-motor drive system is supplied from a single five-phase Space Vector Pulse Width Modulation (S VPWM) Voltage Source Inverter (VSI) and controlled using a vector control scheme, provided that the stator windings are connected in series with appropriate phase transposition. The concept has been developed under the assumption that the inverter voltages are controlled in the stationary dq-reference frame. A fuzzy logic-based speed controller has been constructed and used to drive the two-motor in this work. The two-motor system, inverter system, and fuzzy controller models are implemented and tested using Simulink/Matlab facilities. 1be presented results show the validity of the model to do well for the sake of speed control in wider different operating conditions.
The present work aims to build mathematical models based on experimental data to estimate the mechanical properties of submerged arc weldment. AISI 1020 low carbon steel plates 16mm thickness were welded according to orthogonal array in order to establish the relationship between input parameters (welding current, Arc voltage and welding speed) and output parameters (ultimate tensile stress, yield stress, impact energy and hardness) by submerged arc welding (SAW) process. The relationship between input and output parameters for the welding process are conducted using two suitable mathematical models the first one based on regression analysis, while the second one based on multi input single output ANFIS model for estimation of some mechanical properties of the welded plates. It was found that ANFIS results are closer to the experimental results than regression results. The optimal parameters (which give a maximum value of ultimate tensile strength (UTS), yield stress and impact energy; 446 MPa, 318 MPa and 213 J) are welding current is (380 Amp), Arc voltage is (25 V) and welding speed is (40 cm/min), while the maximum value of hardness number is (228 HV), when current welding is (380 Amp), Arc voltage is (25 V) and welding speed is (25 cm/min).
In this work, a new computerized measurement system for multi-plane flexible rotor balancing has been designed and implemented. This system can be used to modernize and enhance conventional low-speed balancing machines or for field balancing applications. This system adds very important features to balancing machines such as multi-plane flexible rotor balancing, high accuracy, stability, and high dynamic range. Also, the proposed flexible rotor balancing technique permits accurate balancing of high-speed rotors utilizing low-speed balancing machines or field balancing at speeds lower than the critical speeds. The proposed digital Wattmetric technique in conjugation with advanced measurement circuitry have led to significant improvement in balancing accuracy even when the unbalance signal is buried into high level of noise.
In digital signal processing (DSP), FIR digital filter is very important device to deal with particular frequencies of a certain signal to be appropriate for some applications such as communications, sound equalizers, etc. In this paper, FIR filters are adopted to decompose the original sound signal into four signals. Each one is created by one FIR filter and each filter represents a narrow band of frequencies. The filter output is used to drive a certain variable speed drive (VSD) to control the speed of a water pump and light intensity of a colored lamp. This filter output signal is applied to the analog control voltage terminals of the VSD unit to control the frequency and magnitude of the voltage supplied to the lamp and pump. Thus, the heads of the water jets and the light intensity are controlled according to the analog control signals which are created by the FIR filters (The VSD is used to map the filter output into light intensity and water head by controlling the supplied voltage of them). The goal of this study is to design and simulate four sound harmonics bands produced by FIR filters to drive four VSDs which are simulated using V/F ratio constant method for musical fountain operation.
A numerical study of mixed convection inside a horizontal channel with an open square cavity that includes an adiabatic rotating cylinder. The bottom wall of the cavity is heated at a constant temperature, and the remaining walls are adiabatic. The flow is incompressible, laminar and steady state. The equations of continuity, momentum and energy are solved numerically using computational fluid dynamics (CFD) with the commercial software package FLUENT 2019 R1. Reynolds number values of 50, 100 and 150, the Richardson number (0.1 ≤ Ri ≤ 10) and the angular velocity ( ω ) of cylinder is (0.5 ≤ ω ≤ 4) rad/sec with direction counter clockwise. Prandtl number for air flow is ( Pr = 0.7). The results are presented in terms of streamlines, isotherms, and the average Nusselt value is given over the heated bottom cavity. The combined effects of natural and forced convection in and out of the cavity were obtained. The results showed that at low Richardson values, Ri = 0.1 the effect of buoyancy force is neglected. The effect of increasing the cylinder speed is clearly noticeable at low Reynolds values, Re = 50. Average Nusselt values increase with increasing rotational speed of the cylinder for all Richardson values.
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
This work uses different shapes of intake manifold for study the effect on a single cylinder four stroke gasoline engine. A numerical simulation of the flow achieved through five intake manifold designs, using 3D Computational Fluid Dynamic (CFD) software package FLUINT (6.3.). Accordingly, the three-dimensional resolution of Navier-Stokes equations in conjunction with the standard k-ε turbulence model is undertaken to provide knowledge of the air movement nature and examining the intake manifold optimal geometry. Five cases of intake manifold are examined experimentally in order to produce a comprehensive and realistic data set. These data are in the form of engine performance, exhaust gas products and relative AFR for each case separately under different engine speeds. Exhaust gas analyzer type (Infragas-209) is used in the present work to measure exhaust gas concentrations and relative air/fuel ratio ( ). The results were obtained in this investigation showed that a Simulate numerically and experimentally is capable to select the optimized intake system geometry with reliability. Velocity is highest near the outer wall at increased the curvature ratio and pressure is highest near the inner wall at increased the curvature ratio. The secondary flow increases when the engine speeds and curvature ratio increase because of increasing the pressure difference between the inner wall and the outer wall. The effect of these parameters explained on the swirl air movement and tumble inside the cylinder are increasing by increase the engine speed and γ respectively. The increasing in the engine speed and the optimum selection of the manifold which designed enhanced the mixing of the fuel with air. The results showed that the optimized manifold 135º- NE (case 5) due to enhance AFR, fuel consumption and exhaust emissions are improved.
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
The flow control around the airfoil is widely investigated and utilized in the aircraft industry. The benefit of reducing the separation effect and its impact on the aerodynamic performance made the effort on this area is more desirable as this will impact to enhance the flight control as well as to reduce the fuel consumption during the flight. In this paper, the flow control using leading-edge blowing technique has been conducted for NACA0018 airfoil at Reynolds number 6.85 and 13.7 × 10 5 . A CFD analysis has been conducted to examine several flight parameters and blowing speed to explore the benefit of using the blowing in this wing section. The results indicate that the lift coefficient can be enhanced to be increased by 4-6% as compared with no blowing case. However, this increase ratio is affected by the operational Reynolds number and blowing ratio. Higher speed means less benefit from blowing within the limit of blowing ratio of 1. The benefit of using the blowing could come with an increase in the drag at some angle of attack. It is noticed that the blowing technique can generate positive pitching moment at lower angle of attack and can reduce the negative moment when the separation is happening at higher angle of attack. Also, the lesson learned in this paper is that the blowing benefit is more pronounced when the flight is under low Reynolds number environment.
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
Continuously Variable Transmission (CVT) combines the efficiency of manual transmissions with the driving comfort of automatic transmissions while providing an infinite range of gear ratios, improved fuel economy, and enhanced acceleration performance. This study presents a comparative evaluation of CVT performance against manual and automatic transmissions in a parallel hybrid electric vehicle (HEV), focusing on fuel consumption and exhaust emissions. A baseline HEV model equipped with a CVT gearbox was selected from ADVISOR simulation software and subsequently modified by replacing the CVT with manual and automatic transmissions for comparison. Exhaust emissions, including catalytic converter pollutant reactions, were recorded for all configurations. Performance assessments were conducted using several global standard driving cycles to simulate real driving conditions. Results indicated that the CVT configuration achieved superior fuel economy and a significant reduction in exhaust emissions compared with manual and automatic transmissions. This improvement is attributed to the CVT’s effective control of speed ratio and overall transmission efficiency. The findings support the suitability of CVT gearboxes for urban hybrid vehicle applications due to their low fuel consumption and high efficiency in speed ratio control.
In this paper, the influence of thermal residual stress on strength and fracture rotating speed of composite disc is studied and analyzed using finite difference method and laminated plate theory for two types of reinforced composite discs (radial fiber reinforced disc and circumferential fiber reinforced disc). As a result the thermal residual stress will reduce radial and tangential stresses in radial fiber reinforced disc, while it shall increase radial stresses and decrease tangential stresses in circumferential fiber reinforced disc. The existing of residual stresses in composite disc will leads to initiation of crack and begins to propagation near the inner diameter compared to case when neglecting residual stress for cases taken in analysis. It is also verified that the finite difference method is a good tool for stress analysis of composite disc under residual stress effec
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
In this proposed study, all environmental factors affecting the aboveground and buried pipes, such as solar radiation and temperature, and soil temperature, have been studied on the characteristics of flow inside the aboveground and underground pipelines by building a mathematical model using MATLAB based on energy balance equations. From the mathematical model, the effect of solar radiation on the aboveground section of the pipeline is significate. During March and an inlet temperature of 34 °C, the pipeline outlet fluid temperature will rise to 50 °C. Other parameters affecting the aboveground section of the pipeline, such as ambient temperature and wind speed, have a much smaller effect on the fluid temperature, and the temperature difference is approximately 4 °C between the highest and lowest pipeline outlet fluid temperature. The result for the underground section of the pipeline showed that the main affecting parameter on the fluid temperature is the burry depth of the pipeline, the deeper the pipeline depth the lower the temperature variation and the lower fluid temperature can be seen, at 1 meter of bury depth the minimum and maximum fluid temperature was 18 °C and 36 °C respectively, and at 5 meters of bury depth, the minimum and maximum fluid temperature was 26 °C and 31 °C respectively. This study also checks different process parameters. Some of these are fluid flow, pipe diameter, and pipe material. The effect of the fluid flow and pipe diameter has a similar impact on the fluid temperature (while fixing all the other parameters), the higher the fluid flow or the smaller the pipe diameter resulted in a better heat transfer and more considerable temperature difference, and vice versa. The final process parameter, pipe material, had little to no effect on the fluid temperature variation.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Van Kármán vortex street is considered an important phenomenon that accompanies fluid flow, especially when exposed to a certain barrier, as periodic vortexes occur on both sides of the body that rotate in two opposite directions. This phenomenon occurs in the atmosphere around mountains, oceans, seas, and islands. Also, this phenomenon makes it possible to induce a fluid flow around a specific body present in the flow path. In this study, a model for fluid flow around a cylinder of a certain diameter was taken, where the flow near the boundary layers of the cylinder surface moves slower than near the free stream. In addition, the pressure distribution was studied, and it was observed that there is a pressure gradient due to the difference in momentum at the surface of the cylinder in distant areas due to friction. The study area was divided into fine meshes with Fluent software, especially in the irregular areas. The simulation was implemented for Reynolds numbers Re = 100 and Re = 1500 for incompressible flows. Consequently, the equations that do not depend on pressure are difficult to solve. Therefore, methods linking pressure and velocity were adopted, where the pressure-velocity coupling simple method was used. The first-order forward difference scheme was adopted in representing the differential equations as a function of time when performing the simulation. From the steady state and upwards to Reynolds number Re = 100, it was observed that a twain of vortices appeared on the body at a certain speed range. When the state was changed from the stable state to the transitional state, the results changed, as the flow became asymmetric and unsteady due to vortex shedding phenomena, which led to the generation of vortexes in different ways. The U-Velocity curve was studied for two different cases, and the results showed a large discrepancy between the first order and the second order, where the second order had better behavior but required great effort to reach accurate results. Also, pressure-velocity was studied to satisfy mass conservation, and numerical techniques were used to c ompute the equations of Navier-Stokes in CFD, such as SIMPLEC, PISO, and SIMPLE. An acceptable convergence was not reached with the PISO; therefore, the SIMPLE method was adopted. The pressure gradient was drawn around the cylinder, where it was observed that the pressure was greatest at the front of the cylinder and its lowest value at the end.
In this paper, parallel optical array adder fur large-scale 2D Modified Sign-Digjt (MSD) data array is proposed. and implemented to limit the cany propagation to constant steps. The digit-decomposition-plane (DDP) representation technique is expanded to code the 2D an-ay of the MSD nwnber system. The design is based on the logical fonnul.as which are newly derived according to the fundamental parallel addition algorithm for MSD number system using the . . . . featur~ of the DDP coding technique. The optical im plementations scheme is based on classical optical elementS sucb NJ spatial light modulators, ooam combiner.;, beam splitters, mirrors, light source anays, and light detector arrays. The proposed algorithm and itS optical architecture ~ ve useful intrinsic characteristics such as ultra-high speed, constant processini time, and parallel computation on large-scale data arrays. The simulation results insure lhat the proposed arithmetic unit is worked successfully.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
The finite element method is used to simulate the soil vibration behavior due to the Basrah-Baghdad passenger train and its effect on a targeted building in the Al-Ma'qal quarter, Basrah governorate. Three-dimensional dynamic elastic analyses are performed to calculate the particle velocities for a train speed of 120 km/hr. The effectiveness of screening using active (10 m long) open trench barriers with variable depth (2 m - 5 m) and width (0.4 m - 0.8 m), is being studied. For a given trench width (0.4 m), the results of the parametric study revealed a considerable effect of trench depth where the screening capability near the trench is increased by (10.4 %, 26.1 %, 36.3 %) due to a (50 %, 100 %, 150 %) increase in depth. The results are less sensitive to the variation in trench width. The screening capability of a double open (0.4 m × 10 m × 2 m) trench system was also investigated, where a mitigation improvement of (36.4 %) was achieved. The vibration mitigation using single and double trench systems, filled with (40 %) rubber content mixture, was also analyzed. It is concluded that using the additional passive trench increases the mitigation of the single system by around 19.1 %. An important finding is that the (40 % rubber + 60 % native cohesive soil) mixture proved to be a good filling material, since the infilled-trench systems produced comparable screening ratios to the open systems, where (97.7 %) and (85.4 %) were accomplished for the single and double systems, respectively.
The desalination market is gradually growing as a result of the significant water scarcity in various regions throughout the world. Concentrated solar power (CSP) can be used to power distillation, which is an effective method for addressing water shortages in areas where there is both a severe lack of water and abundant direct normal irradiation. CSPs are ideal candidates for the advancement of desalination technologies due to their capacity to produce both thermal and electricity energy. This review article offers a comprehensive of the current status of cutting-edge CSP-desalination systems. The paper reviews previously published studies conducted by researchers in the field of multi-effect desalination using concentrated solar collectors, and they are classified into two main types. Exclusively freshwater generation and freshwater / electricity cogeneration. In addition, the paper reviews conventional desalination. This review illustrates that there are numerous prospective methods for integrating desalination systems into CSPs. Potential areas for future investigation in CSP-desalination systems. In particular, the most significant obstacles to be surmounted are lowering the costs and efficiency improvements of solar repayment and desalination equipment. A potential method to expedite the commercialization of these plants is to develop innovative strategies that optimize thermal efficiency and reduce costs. Environmental factors (solar radiation intensity, ambient temperature and wind speed) and design factors (solar field area, number of mirrors, number of stages, steam temperature, steam quantity and pressure) are the main effective parameters that affect the distilled water production process. In general, the CSP desalination systems are environmentally and technically appealing; however, there remains substantial progress to be made in order for these plants to be commercially viable.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Bearing fault diagnosis is essential for the maintenance, durability, and reliability of rotating machines. It can minimize economic losses by removing unplanned downtime in the industry due to the failure of rotary machines. In bearing fault detection, developing fault features extraction techniques that can successfully applicable for various fault severity and different operating conditions is still a critical issue. In the current work, the feature extraction technique is a combination between pre-processing algorithms and envelope analysis method. In the pre- processing stage, the autoregressive (AR) model is used to filter the original signal and remove the deterministic vibration sources, as well as maintain the signal representing the condition of the bearing without contaminating noises. Then, the most suitable frequency band is selected based on the spectral kurtosis (SK) analysis. This band contains the signature frequencies of the roller bearing. After that, envelope analysis is employed for detecting faults at different severity. Finally, the features represented the peaks at fundamental fault frequencies are automatically selected from the envelope spectrum. By analyzing all diagnoses results, it is found that the presented method effectively extracts the features at calculated resonance bearing frequencies and proves the significance of the enhancements in a pre-filtering stage in the overall detection performance. Also, it can benefit from these features in the fault classification fields at different speeds because it is independent of speed variation.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
The dieless drawing process is an innovative method emanated and appeared in coincidence with development of the concept of metal superplasticity. It is utilized from the local heating of a wire or tube to a specified temperature and followed by a local cooling, so an additional deformation is inhibited. In this study, a special dieless drawing machine was designed to carry out an experimental program on SUS304-stainless steel wire having diameter of (1.6-2) mm to investigate the main process parameters such as speeds, heat quantity, heating coil width and heating-cooling separation distance. Also, a numerical model based on thermo-mechanical analysis was developed and validated with experimental program. Furthermore, an artificial neural network ANN model based on current experimental data was prepared to predict the dieless drawing behavior. A maximum area reduction of 40.7% was obtained in single pass. A 3.12mm/s feeding velocity and 4.97mm/s drawing velocity were realized through the experimental tests. The results showed that both drawing force and wire profile were effected by increasing of feeding speed, heating coil width and separation distance. Also, it is confirmed that strain rate was reduced by increasing the heating coil width and the reduction ratio was promoted. A maximum error of 21% was recorded between ANN model and experimental results. The results showed a good agreement among experimental, numerical and ANN models.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Orthogonal frequency division multiplexing (OFDM) has become a popular modulation method in high-speed wireless communication systems due to its high data rate transmission capability and robustness against multipath fading effects. One of the major drawbacks of OFDM at the transmitter side is the high peak-to-avenge power ratio (PAPR) of the OFJ)M signal. In this paper, an algorithm is proposed to reduce the peak-to-average power ratio of OFDM signal with a large number of sub-carriers. This algorithm is based on the tone reservation method. The computer simulation tests show that the suggested algorithm reduces the PAPR to a factor of S.2S dB and needs less number of iterations as compared with the traditional tone reservation algorithm.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
The purpose of this paper is to determine a stress intensity factor experimental and numerically in the linear region by using a CT specimen of ductile material with a thickness of 15 mm, a width of 30 mm, and pre-crack 1.3 mm this dimension according to ASTM-E399-12 [1], by pulling the specimen in a 600 kN universal testing machine at a very slow speed rate of 0.5 mm/min. The load is applied until the fracture is accrued, the computer-controlled universal testing machine gives the value of the load and the displacement transducer gives a crack mouth opening displacement. The result showed experimental K I is equal to 75.412 MPa √ m, and numerical K I is equal to74.576 MPa √ m, this test showed a very slight decrease in FEA stress intensity factor compared to that in an experimental result which means the stress intensity factor, K I remains very close between experimental and numerical with an error percentage of about (1.12 %). The finite element analysis provides the best approximation to true fracture toughness values, and it can be used to acquire close parameters if experimental testing is not possible.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
This paper introduces a radial distribution feeder protection scheme based on certain features extraction from current signals measurement at the substation. The features are captured using the discrete wavelet transform (DWT). Two digital signals processing methods are used to introduce those features to the 1) fault detection 2) identification and 3) localization schemes; the first one is the energy method and the second one is the root mean square method. For the purpose of fault type identification, two systems are tested and compared, a Fuzzy Inference System (FIS) and Artificial Neural Network (ANN). Fault location scheme is then built based on ANNs. An effort is made to reduce the computational burden and the speed of detection provided by the fault detection and identification schemes. Since the short circuit faults are the most likely types of faults that can occur in power systems, the ten types of these faults taking into account different fault resistances are simulated in MATLAB environment and the protection scheme is built based on the idea of over current. The power quality disturbances such as switching transient events on the feeder is also taken into account in order to build a reliable and secure protection scheme.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Many applications consider floating point arithmetic as a key component of the computations. Combined decimal/binary arithmetic becomes an important topic supports high speed decimal/binary applications. A new 64-bit (16×16 digit) combined decimal/binary multiplier is proposed and implemented in this work that can be used for both fused multiply add (FMA) and multiplier unit. A new partial products reduction tree is shared between decimal and binary multiplier unit. The valuation and comparison result between the proposed multiplier and the previous most recent works shows 4.66 % less delay than combined decimal/binary multiplier and 19.33 % less delay than fastest standalone decimal multiplier.
This paper is concerned with a stress analysis in a bearing under unbalanced fon:es of the jownal. Some aspects of mathematical modeling of rotating structW'Cs were considered. "Finite Element Method'' is fom1ulated for modeling rotating structures. As an application, a test rotor mounted on two-lobe hydrodynamic bearings is presented. Unbalance response calculations for various unbalance magnitudes are ca1Ticd out in the bearing location. The bearing coefficients were found at rotational speed of 4,000 rpm. An accurate identification of bearing force parameters, i.e. stiffness and damping coefficients is presented by a classical linearized model. The bearing support forces in tlexiblc rotor-bearing systems are presented as a function of unbalance response of the journal. The calculation of the bearing stress due to rotor w1balance are carried out using ANSYS. The ANSYS program gives a good aids in understanding the ~tress analysis in the bearing under the action of journal rotation.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
This study investigates the deep drawing process of carbon fiber-reinforced high-density polyethylene (CF-HDPE) composites through experimental and numerical approaches. The experimental part involved fabricating CF-HDPE sheets and conducting deep drawing operations under controlled parameters (punch speed, temperature, and forming depth) to evaluate material behavior and mechanical properties. Numerically, finite element analysis (FEA) using ABAQUS simulated the forming process, analyzing stress distribution, strain development, and material deformation under varying conditions. Results revealed that increasing forming depth and decreasing forming temperature elevated the required forming force. Comparisons between experimental and numerical outcomes showed consistent trends, though some differences arose due to factors like friction and material nonlinearity. The findings contribute to optimizing deep drawing processes for composite materials, enhancing manufacturing precision, and minimizing material defects.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
For shorter landing and take-off path in airports, the aircrafts should reduce their speed with keeping high lifting force. This paper is to identify solutions to increase the lift force of the wing significantly under several flight scenarios (such as takeoff and landing) using leading-edge slats and their relationship with the dynamic parameters of the aerodynamic wing. The study is performed by the use of ABAQUS 2016 software. The problem is solved for turbulent flow and 2-dimensional composite wing at constant Reynolds’s number of (6.49 × 10 5 ) and constant boundary conditions. Various depths have been used for the auxiliary airfoil at constant width and gap. All stresses at the wing base were obtained. The pressure distribution on the airfoil surface was determined, air velocity distribution was tracked over the surface, lift and drag forces and their coefficients were computed. The results show that the highest value of the lift coefficient is 0.489 at the depth (-3 %) of the wing chord, it decreases when the depth of the slat becomes zero %, and the rise returns with increasing depth to (4 %), but it does not reach the maximum value, while the highest drag coefficient was (1.89) at depth (4 %) of the wing chord. The maximum value of Von Mises stress was found at depth of 4 % with value of 1.605 × 10 5 Pa.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Crow Search Algorithm is an innovative meta- heuristic optimization algorithm. In this paper, chaotic maps are combined into Crow Search Algorithm to increase its global optimization. Ten variant chaotic maps are used and the Tent map is found as the best choices for high dimensional problems. The novel Chaotic Crow Search Algorithm is relied on the substitution of a random location of search space and the awareness parameter of crow with chaotic sequences. The results show that the chaotic maps are able to enhance the performance of the Crow Search Algorithm. Also the novel Chaotic Crow Search Algorithm outperforms the conventional Crow Search Algorithm, first version of Chaotic Crow Search Algorithm, Genetic Algorithm, and Particle Swarm Optimization Algorithm from the point view of speed convergence and the function dimensions.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Several geometrical elements influence the aerodynamic properties of the Darrieus vertical axis wind turbines (VAWTs). Many extant studies have examined properties, such as solidity, pitching axis position ( x /c), length of chord (c), blade quantity (N), diameter (d) of the rotor, and aspect ratio. However, not many have examined the shape of the airfoil (AF), which is a vital property that remains to be thoroughly investigated. Therefore, this present study used computational fluid dynamics (CFD) to investigate many airfoils blade characteristics, such as blade thickness (BT), maximum camber ratio (MCR), MCR location (MCRL), and air speed (AS), to determine their impact on VAWT performance. The results demonstrate a blade thickness BT of 10 to 12%, MCR of 0 to 22%, and MCRL of 24 to 23% yield a comparatively high coefficient of power, adequate optimal blade rotation to airspeed ratio (TSR), broader operational area, and high band efficiency while air velocities of 15 to 10% yield a comparatively higher power coefficient.
The solar chimney is a natural draft device that uses solar radiation to provide upward momentum to the in-flowing air, thereby converting the thermal energy into kinetic energy through an air turbine which in turn can be converted into electrical energy. The main parts of the solar chimney power plant are a large circular solar collector, a tall chimney, and an air turbine. In this paper, a theoretical study was performed to evaluate the performance of a solar chimney power plant system in Basrah City, where sunny days and solar radiation are high. A mathematical model was developed to study the effect of various parameters on the output power of the solar chimney. I1 was found that the output power depends strongly on the chimney tall and the difference between the collector air temperature and the ambient air temperature as well as the outside heat transfer coefficient, which essentially depends on the wind speed.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
This study focuses on the design and construction of an automated device for evaluating the scratch resistance of polymeric materials by measuring the force required to produce surface scratches and calculating the corresponding friction coefficient from device input–output data. The device was fabricated using locally available materials, with several components manufactured in local mechanical workshops. It comprises four main subsystems: mechanical components, scratching mechanism, electrical and electronic units, and an operating control program. The developed device offers the following specifications: normal load range of 0.1–325 N, sliding speed of 1–35 mm/s, tangential force measurement capacity of 0.1–294 N via a load cell, sample dimensions of 10–195 mm in length, 10–125 mm in width, and 0.25–50 mm in thickness, a maximum scratch length of 195 mm, and an adjustable indenter height ranging from 0.25 to 50 mm above the platform surface. Scratch testing and friction coefficient measurements were conducted on pure PMMA and PMMA reinforced with silicon dioxide (SiO₂) nanoparticles. Experimental results demonstrated increased scratch resistance and reduced friction coefficients with higher SiO₂ weight ratios. Additionally, the performance evaluation confirmed that the designed device is capable of accurately and rapidly measuring the tangential forces associated with scratching through a simple operational procedure.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
Solar desalination uses solar radiation to convert saline or seawater into clean water and is increasingly crucial due to growing pollution from industrial and automotive sources. Although solar stills offer a sustainable solution, they face challenges in terms of production efficiency. This study presents a new structural design for solar stills, which incorporates advanced insulation materials, a well-designed distillate channel, and an inclined base to enhance productivity. The research explores how different climatic conditions such as wind speed, solar radiation, and atmospheric humidity affect solar still performance. Seven experimental setups were evaluated, comparing traditional inclined stills with advanced closed-loop systems. The results demonstrated that closed-loop systems improved productivity by 28.6% compared to open-loop systems. Additionally, moderate wind speeds increased productivity by 20.82%, while partial cloud cover and light rain decreased productivity by 52.15% and 12.9%, respectively. However, light rain also enhanced condensation efficiency by cooling the glass surface. This study highlights the importance of incorporating environmental factors into the design and optimization of solar still systems for improved performance.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Modeling and simulation of non-linear quarter-car suspension system for two air spring models (traditional and dynamic new air spring) are contrasted in terms of (RMS) sprung mass acceleration, dynamic load coefficient, the vertical displacement, they are compared. Two and three (DOF) of the mathematical quarter models are implemented in MATLAB/Simulink platform. The Ride Comfort (RC), Dynamic Load Coefficient (DLC) and Road Handling (RH) responses are evaluated as objective functions respectively considering a vehicle speed at 72 km/h and road ISO Class B. The obtained results indicate that the vertical displacement, the (RMS) of the sprung mass acceleration, and dynamic load coefficient values with the new air model system decrease by 10.7 %, 30.6 %, and 13.49 % respectively, in comparison to a tradition suspension system, this one gives more comfort and effortless handling.
Experimental investigation was conducted on low speed wind tunnel with (50 mm x100 mm) rectangular working section. Five smooth circular cylinders, as bluff bodies were applied. Cylinders diameters are 12.5, 15, 17, 35, and 37 mm which experience blockage ratio of 12.5%, 15%, 17%, 35%, and 37%, respectively. The range of Reynolds No. and air velocity for present study is 0.7x10^4-5x10^4 and 10-20 m/s respectively which are more applicable in engineering field. The experiments were carried out in fluid mechanics laboratory, Faculty of engineering and technology, Sebha University, Libya. Results indicate that cylinders of blockage ratio of 35% and 37% experience lower pressure coefficients around bodies, lower velocity distribution in the wake, and higher drag coefficients. Drag coefficient correction is agreed with unconfined flow for blockage ratio less than 17%. Wake and buoyancy blockages may have effect on models of higher blockage ratios.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
Fracture mechanics approach is important for all mechanical and civil projects that might involve cracks in metallic materials the purpose of this paper is to determine a crack tip opening displacement fracture toughness experimentally, also study the effect of thickness on CTOD fracture toughness of low carbon steel and study the effect of Wire Electrical Discharge Machine (WEDM) to have a pre-crack, instead of fatigue pre-crack by using a CT specimen of low carbon steel with a thickness of (8,10, and15 mm), a width of 30mm, crack length of 15mm, and pre-crack of 1.3mm for all samples, this dimension according to ASTM-E399-13, by pulling the specimen in a 100 KN universal testing machine at a slow speed rate of 0.5 mm/min, the load applied on the specimen is generally a tension load. The crack tip plastically deforms until a critical point P C at this moment a crack is initiated. The computer-controlled universal testing machine gives the value of the load and the displacement transducer gives a crack mouth opening displacement. Critical crack tip opening displacement CTOD is found with the plastic hinge model (PHM) method. The result showed the stress intensity factor K I increases with increased loading in the elastic region and t he thickness effect refers to the effect of the plastic zone at the crack tip on the stress intensity factor, In a thin specimen, a plastic zone is large at the fracture tip leads to a high-stress intensity factor at the fracture tip but in the thick specimen, on the other hand, has a small a plastic zone and a low-stress intensity factor around the crack tip. The fracture toughness is found to increase with an increase in the thickness of specimens.
This paper describes a study of traffic behavior at AL-Jumhoryia street in Baghdad city. The objective is to use simulation program OSPSM to evaluate the performance of on street parking. The first stage of this research project takes the basic measurements carried out using video camera. The basic measurements are traffic flow, operating speed, parking time, unparking time, gap, and average duration. The second stage of the simulation program OSPSM was to run it using all the observed input parameters to obtain some measures of effectiveness such as the delays caused to through vehicles, the delays caused to parked vehicles, reduction in capacity, turnover rate, Parking Index, Parking accumulation. The main conclusion to the performance of on street parking is that it is reasonable, the average delay of parked vehicles and through vehicles at AL-Jmahory street is accepted value.
In this paper, image deblwring and denoising are presented. The used images were blurred either with Gaussian or motion blur and corrupted either by Gaussian noise or by salt & pepper noise. In our algorithm, a discrete wavelet transform is used to dJvide the image into two parts. This partition will help in increasing the manipulation speed of images that are of the big sizes. Therefore, the first part represents the approximation coefficients, that a blur is reduced b,y using the modified fixed-phase iterative algorithm. While the second part represents the detail coefficients, that a noise is removed by using the BayesShrink wavelet thresholding method.