## THERMAL SCIENCE

International Scientific Journal

### CFD ANALYSIS OF HELICAL NOZZLES EFFECTS ON THE ENERGY SEPARATION IN A VORTEX TUBE

**ABSTRACT**

In this article computational fluid dynamics (CFD) analysis of a three-dimensional steady state compressible and turbulent flow has been carried out through a vortex tube. The numerical models use the k-ε turbulence model to simulate an axisymmetric computational domain along with periodic boundary conditions. The present research has focused on the energy separation and flow field behavior of a vortex tube by utilizing both straight and helical nozzles. Three kinds of nozzles set include of 3 and 6 straight and 3 helical nozzles have been investigated and their principal effects as cold temperature difference was compared. The studied vortex tubes dimensions are kept the same for all models. The numerical values of hot and cold outlet temperature differences indicate the considerable operating role of helical nozzles, even a few numbers of that in comparing with straight nozzles. The results showed that this type of nozzles causes to form higher swirl velocity in the vortex chamber than the straight one. To be presented numerical results in this paper are validated by both available experimental data and flow characteristics such as stagnation point situation and the location of maximum wall temperature as two important facts. These comparisons showed reasonable agreement.

**KEYWORDS**

PAPER SUBMITTED: 2011-05-31

PAPER REVISED: 2011-07-30

PAPER ACCEPTED: 2011-08-01

**THERMAL SCIENCE** YEAR

**2012**, VOLUME

**16**, ISSUE

**1**, PAGES [151 - 166]

- Ranque, G.J., Experiences sur la détente giratoire avec simultanes d'un echappement d'air chaud et d'un enchappement d'air froid, J. Phys.Radium, 4 (1933), pp. 112-114
- Hilsch, R., Die expansion von gasen im zentrifugalfeld als kälteproze, Z. Naturforschung 1(1946), pp. 208-214
- Kurosaka, M., Acoustic Streaming in Swirling Flows, J. Fluid Mech., 124 (1982), pp. 139-172
- Stephan, K., et al., An Investigation of Energy Separation in a Vortex tube, Int. J. Heat Mass Transfer, 26 (1983), pp. 341-348
- Ahlborn, B., Gordon, J., The Vortex Tube as a Classical Thermodynamic Refrigeration Cycle, J. Appl. Phys, 88 (2000), pp. 645-653
- Aljuwayhel, N.F., Nellis, G.F., Klein, S.A., Parametric and Internal Study of The Vortex Tube Using a CFD Model, Int. J. Refrig., 28 (2005), pp. 442-450
- Behera, U., et al., CFD Analysis and Experimental Investigations Towards Optimizing The Parameters of Ranque-Hilsch Vortex Tube. Int. J. Heat and Mass Transfer, 48 (2005), pp. 1961-1973
- Skye, H.M., Nellis, G.F., Klein, S.A., Comparison of CFD Analysis to Empirical Data in a Commercial Vortex Tube. Int. J. Refrig., 29 (2006), pp. 71-80
- Chang, H.S., Experimental and Numerical Studies in a Vortex Tube, Journal of Mechanical Science and Technology, 3 (2006), pp. 418-425
- Eisma., Promvonge, S., Numerical Investigations of The Thermal Separation in a Ranque-Hilsch Vortex Tube. Int. J Heat and Mass Transfer , 50 (2007), pp. 821-32
- Kirmaci V., Optimization of Counter Flow Ranque-Hilsch Vortex Tube Performance Using Taguchi Method, International Journal of Refrigeration, 32 (2009), pp. 1487-1494
- Akhesmeh, S., Pourmahmoud, N., Sedgi, H., Numerical Study of the Temperature Separation in the Ranque-Hilsch Vortex Tube, American Journal of Engineering and Applied Sciences, 3 (2008), pp. 181-187
- Xue, Y., Ajormandi M., Kelso, R., A Critical Review of Temperature Separation in a Vortex Tube, Journal of Experimental Thermal and Fluid Science, 8 (2010), pp. 1367-1374
- Bramo, A.R., Pourmahmoud, N., A Numerical Study on The Effect of Length to Diameter Ratio and Stagnation Point on The Performance of Counter Flow Vortex Tube, Aust. J. Basic & Appl. Sci., 4 (2010), pp. 4943-4957
- Bramo, A.R., Pourmahmoud, N., CFD Simulation of Length to Diameter Ratio Effect on The Energy Separation in a Vortex Tube, Thermal Science, In Press
- Pourmahmoud, N., Bramo, A.R., The Effect of L/D Ratio on The Temperature Separation in The Counter Flow Vortex Tube , IJRRAS, 6 (2011), pp. 60-68
- Hossein Nezhad, A., Shamsoddini, R., Numerical Three-Dimensional Analysis of The Mechanism of Flow and Heat Transfer in a Vortex Tube , Thermal Science, 4 (2009), pp. 183-196
- Kirmaci, V., Uluer, O. An Experimental Investigation of the Cold Mass Fraction, Nozzle Number, and Inlet Pressure Effects on Performance of Counter Flow Vortex Tube, Journal of Heat Transfer, 131 (2009), pp. 603-609
- Prabakaran, J., Vaidyanathan S., Effect OF Diameter of Orifice and Nozzle on the Performance of Counter Flow Vortex Tube, International Journal of Engineering Science and Technology, 4 (2010), pp. 704-707
- Shamsoddini, R., Hossein Nezhad, A., 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), pp. 774-782 Fulton, C.D., Ranque's tube, J Refrig Eng., 5 (1950), pp. 473-479 KURNIA, J.C., SASMITO. A.P., MUJUMDAR. A.S., Laminar Convective Heat Transfer for In-Plane Spiral Coils of Non-Circular Cross Section Ducts: A computational fluid dynamics study, Thermal science, (2011), in press