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Go to Editorial ManagerThe present numerical and experimental work investigates the performance of electromagnetic flowmeter (EMF) for measuring the flow rate of annular flow. Adaptive finite difference technique is used for the numerical calculations and the experimental work is done by making some modification on an existing electromagnetic flowmeter and its testing rig. The performance of the modified EMF is evaluated using two criteria namely, the flowmeter sensitivity S and the conventional weight function non uniformity ε. These two criteria were checked against two parameters; thickness of flowing water (δ) and the electrodes angular position (θe). Experimentally, three different water thickness (δ/Ro = 0.216, 0.373, 0.218) and three electrode position (θe=0o, 11.25o, 45o) were studied. The theoretical and experimental results have showed that these devices work properly in the annular flow case, where the most suitable electrode position in the annular flow was found to be in the conventional position (θe =0o).
The weight function prescribing the sensitivity of the electromagnetic flowmeter (EM}') to the changes in the velocity profiles must be as much as possible uniformly distributed through the measuring volume. The most commonly used criterion of the weight function distribution is a statistical quantity ( e criterion) which deals with only the axial component of the weight vector. In the present work, attempt 10 introduces a more revealing and accurate criterion to the EMF performance was studied. The curl of the weight function vector over the measuring volume has been considered and formulated (and termed as e ) in such a mathematical expression that takes Into account the contributions of the three components of the weight vector regardless of the geometry of the cross-sectional area of the flow. In addition, a numerical solution of a previously defined criterion (ey) is presented here for the first time in order to compare the validity of the newly introduced criterion. The results showed that the present new criterion e is closely harmonious with the previously defined criteria 8 and Si.. in the conventional flow cases. The results and the configuration of the formula of the present criterion, which is independent of the flow cross-sectional led us to conclude that is more reliable and applicable than other existing criteria.
Electromagnetic flowmeters have proven their merit in· measuring the flow rate of conducting liquids in fully-filled pipes. In contrast with the most of the published works about the electromagnetic flowmetcr, the attentions were focused in this work into the use of these devices in partially-filled pipes. In this application these devices suffer from the problem of different outputs with different liquid level for the same flow rale. We studied whether the process of changing the distribution of the magnetic field through the measuring section improves lhe tlo,~rneter performance against this drawback or not. An adaptive numerical mesh was used in predicting the flow induced signal and its response to the liquid level. The induced signal was assumed to he picked up by a pair of point electrodes tested for different angular positions. The results showed that the performance of the electromagnetic flowmeter in partially-filled pipes could be appreciably improved by making the magnetic field progtessively decreases from top to the bottom of the flowmeter. When the lower magnet coil is excited by a current one-half lower than the upper coil together with two point electrodes placed at 22° below the flowmetcr horizontal centerline, the flowmeter performance offer more stable sensitivity.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.
Electromagnetic flowmeters measure flow rate of the electrically conducting liquids. Its operation is based on Faraday's principle of induction. In many situations the pipe may be partially filled where in this case the analysis of the flowmeter equation is widely altered and the numerical solution may diverge. In this paper we have established a new numerical formulation, based on finite difference method, which adaptively refines the mesh until the desired solution converges to a certain accuracy. The representation of the flowmeter equations in the polar axis of the solution domain (cylindrical cut from it the empty portion) can result in the singularities in the solution. To avoid these singularities, the grids are shifted one half mesh width from the polar axis. The number of iterations that gives convergence is appreciably reduced via this numerical technique. The build algorithm of the adaptive numerical solution led us to determine, for each liquid level, the optimum angular position of the electrodes that gives maximum accuracy i.e. minimum sensitivity to the changes in the velocity profile of the liquid to be metered.