Cover
Vol. 14 No. 1 (2014)

Published: January 31, 2014

Pages: 122-135

Original Article

NUMERICAL STUDY OF THE INITIAL PRESSURE AND DIAMETERS RATIO EFFECT ON THE JET EJECTOR PERFORMANCE

Abstract

In this paper, computation fluid dynamics model (CFD) is used to simulate a turbulence flow fields along the jet ejector. A Steady-state 2-D compressible flow model utilities the standard k- turbulent model has been used. The performance of jet ejector is simulated by FLUENT 6.3 (code) and GAMBIT software, using finite-volume scheme to solve transport NAVIER STOKE equations. The objective of this study is to investigate the high- performance of jet ejector geometry (mass flow and head ratio) nozzle to throat diameter at eight cases (DN/DT) with different initial pressure. Research is performed to optimize jet performance by varying initial pressure and nozzle diameter ratios from (1/8) to (8/8). To increase understanding of the axial velocity distribution at an important regions along the ejector, three regions are chosen, at inlet (1,3), nozzle exit(2) and midpoint of throat(4), with an important different diameters ratio cases 1,2,3,5,7 and 8 respectivly. The comparison of these results is presented by the axial velocity magnitude, mass and head ratio of the ejector at the above cases. Results show that higher pressure ratio and mass ratio (high performance) occur when the nozzle to throat diameter ratio (DN/DT) was (5/8) and (1/8) respectively. Also mass ratio is decreased at all initial pressure when the diameter ratio increased.

References

  1. Shengqiang Shen, Xiaoping Qu, Bo Zhang, Saffa Riffat and Mark Gillott "Study of a gas-liquid ejector and its application to a solar-powered bi- ejector refrigeration system" Applied Thermal Engineering 25 (2005) 2891- 2902
  2. Huang, Chang, Wang and Petrenko "A 1-D analysis of ejector performance" International Journal of Refrigeration 22 (1999) 354-364
  3. Mark J. BERGANDER " refrigeration cycle with two-phase condensing ejector" International Refrigeration and Air Conditioning Conference at Purdue, July 17-20, 2006
  4. Zhang, X.J. and Wang, R.Z" A new combined refrigeration and adsorption-ejector heating hybrid system powered by solar energy" Applied Thermal Engineering 22 (2002) 1245-1258.
  5. Kanjanapon Chunnanond and Satha Aphornratana " Ejectors: applications in refrigeration technology" Renewable and Sustainable Energy Reviews 8 (2004) 129-155
  6. Hisham El-Dessouky Hisham Ettouney, Imad Alatiqi and Ghada Al- Nuwaibit "Evaluation of steam jet ejectors" Chemical Engineering and Processing 41 (2002) 551-561
  7. Igor J. Karassik, Joseph P. Messina, Paul Cooper and Charles C. Heald "pump handbook" third edition,
  8. Ayad Mahmoud Salman, "Turbulent Forced Convection Heat Transfer in the Developing Flow through Concentric Annuli", Mechanical Engineering Department of University of Technology, July 2003.