## THERMAL SCIENCE

International Scientific Journal

### NUMERICAL INVESTIGATION ON FLOW BEHAVIOR AND ENERGY SEPARATION IN A MICRO-SCALE VORTEX TUBE

**ABSTRACT**

There are a few experimental and numerical studies on the behaviour of micro-scale vortex tubes. The intention of this work is to investigate the energy separation phenomenon in a micro-scale vortex tube by using the computational fluid dynamic. The flow is assumed as steady, turbulent, compressible ideal gas, and the shear-stress transport sst k-w is used for modeling of turbulence phenomenon. The results show that 3-D CFD simulation is more accurate than 2-D axisymmetric one. Moreover, optimum cold-mass ratios to maximize the refrigeration-power and isentropicefficiency are evaluated. The results of static temperature, velocity magnitude and pressure distributions show that the temperature-separation in the micro-scale vortex tube is a function of kinetic-energy variation and air-expansion in the radial direction.

**KEYWORDS**

PAPER SUBMITTED: 2012-03-16

PAPER REVISED: 2012-07-10

PAPER ACCEPTED: 2012-10-24

**THERMAL SCIENCE** YEAR

**2015**, VOLUME

**19**, ISSUE

**Issue 2**, PAGES [619 - 630]

- G. Ranque, Experiments on expansion in a vortex with simultaneous exhaust of hot air and cold air, Le Journal de Physique et le Radium (Paris),4 (1933),pp. 112-114.
- G. Ranque, "Method and apparatus for obtaining from a fluid under pressure two outputs of fluid at different temperatures," US Patent 1:952,281, 1934.
- R. Hilsch, The use of the expansion of gases in a centrifugal field as cooling process, Review of Scientific Instruments,18 (1947),2, pp. 108-113.
- S. Eiamsa-Ard and P. Promvonge, Numerical simulation of flow field and temperature separation in a vortex tube, International Communications in Heat and Mass Transfer,35 (2008),8, pp. 937-947.
- M. Saidi and M. Valipour, Experimental modeling of vortex tube refrigerator, Applied thermal engineering,23 (2003),15, pp. 1971-1980.
- C. Gao, et al., Experimental study on a simple Ranque-Hilsch vortex tube, Cryogenics,45 (2005),3, pp. 173-183.
- O. Aydin and M. Baki, An experimental study on the design parameters of a counterflow vortex tube, Energy,31 (2006),14, pp. 2763-2772.
- M. Hamdan, et al., Experimental analysis on vortex tube energy separation performance, Heat and Mass Transfer,47 (2011),12, pp. 1637-1642.
- Y. T. Wu, et al., Modification and experimental research on vortex tube, International Journal of Refrigeration,30 (2007),6, pp. 1042-1049.
- S. U. Nimbalkar and M. R. Muller, An experimental investigation of the optimum geometry for the cold end orifice of a vortex tube, Applied thermal engineering,29 (2009),2-3, pp. 509-514.
- M. S. Valipour and N. Niazi, Experimental Modeling of a Curved Ranque-Hilsch Vortex Tube Refrigerator, International Journal of Refrigeration,34 (2011),4, pp. 1109-1116.
- W. Fröhlingsdorf and H. Unger, Numerical investigations of the compressible flow and the energy separation in the Ranque-Hilsch vortex tube, International Journal of Heat and Mass Transfer,42 (1999),3, pp. 415-422.
- J. Keyes Jr, An experimental study of gas dynamics in high velocity vortex flow, Proceedings of the Heat Transfer and Fluid Mechanics Institute, Stanford University, Oak Ridge National Laboraty, Tennessee, 1960,pp. 31-46.
- U. Behera, et al., CFD analysis and experimental investigations towards optimizing the parameters of Ranque-Hilsch vortex tube, International Journal of Heat and Mass Transfer,48 (2005),10, pp. 1961-1973.
- N. F. Aljuwayhel, et al., Parametric and internal study of the vortex tube using a CFD model, International Journal of Refrigeration,28 (2005),3, pp. 442-450.
- H. M. Skye, et al., Comparison of CFD analysis to empirical data in a commercial vortex tube, International Journal of Refrigeration,29 (2006),1, pp. 71-80.
- S. Eiamsa-ard and P. Promvonge, Numerical investigation of the thermal separation in a Ranque-Hilsch vortex tube, International Journal of Heat and Mass Transfer,50 (2007),5-6, pp. 821-832.
- M. Ameri and B. Behnia, The study of key design parameters effects on the vortex tube performance, Journal of Thermal Science,18 (2009),4, pp. 370-376.
- T. Farouk and B. Farouk, Large eddy simulations of the flow field and temperature separation in the Ranque-Hilsch vortex tube, International Journal of Heat and Mass Transfer,50 (2007),23-24, pp. 4724-4735.
- T. Farouk, et al., Simulation of gas species and temperature separation in the counterflow Ranque-Hilsch vortex tube using the large eddy simulation technique, International Journal of Heat and Mass Transfer,52 (2009),13-14, pp. 3320-3333.
- A. H. Nezhad and R. Shamsoddini, Numerical three-dimensional analysis of the mechanism of flow and heat transfer in a vortex tube, Thermal Science,13 (2009),4, pp. 183-196.
- R. Shamsoddini and A. H. Nezhad, Numerical analysis of the effects of nozzles number on the flow and power of cooling of a vortex tube, International Journal of Refrigeration,33 (2010),4, pp. 774-782.
- T. Dutta, et al., Comparison of different turbulence models in predicting the temperature separation in a Ranque-Hilsch vortex tube, International Journal of Refrigeration,33 (2010),4, pp. 783-792.
- A. F. Hamoudi, "An Investigation of a Micro-Scale Ranque-Hilsch Vortex Tube," MS Thesis, Mechanical, Automotive and Materials Engineering Department, University of Windsor,Windsor, ON, Canada, 2006.
- L. Dyskin and P. Kramarenko, Energy characteristics of vortex microtubes, Journal of Engineering Physics and Thermophysics,47 (1984),6, pp. 1394-1395.
- A. Hamoudi, et al., Performance Characteristics of a Microscale Ranque-Hilsch Vortex Tube, Journal of Fluids Engineering,130 (2008),pp. 101206.
- Z. Zhang, Nano/microscale heat transfer, McGraw-Hill Professional, 1st ed. 2007.
- F. R. Menter, Two-equation eddy-viscosity turbulence models for engineering applications, AIAA journal,32 (1994),8, pp. 1598-1605.
- T. Cebeci, Analysis of turbulent flows, Elsevier, 2nd ed. 2004.
- T. Cebeci, Turbulence models and their application: efficient numerical methods with computer programs, Horizons Pub. and Springer. 2004.
- "FLUENT 6.3 User's Guide," Fluent Inc., 2006.
- Y. Xue, et al., A critical review of temperature separation in a vortex tube, Experimental Thermal and Fluid Science,34 (2010),8, pp. 1367-1374.
- M. Yilmaz, et al., A review on design criteria for vortex tubes, Heat and Mass Transfer/Waerme- und Stoffuebertragung,45 (2009),5, pp. 613-632.
- S. V. Patankar, Numerical heat transfer and fluid flow, Hemisphere Pub. 1980.
- H. K. Versteeg and W. Malalasekera, An introduction to computational fluid dynamics: the finite volume method, Prentice Hall. 2007.
- U. Behera, et al., Numerical investigations on flow behaviour and energy separation in Ranque-Hilsch vortex tube, International Journal of Heat and Mass Transfer,51 (2008),25-26, pp. 6077-6089.