1. Tehran – Tarbiat Modares University 16 – 17 May 2017
In the name of God
The 8th National Conference on CFD Applications in Chemical & Petroleum Industries
Tehran – Tarbiat Modares University
16 – 17 May 2017 1

2. Investigation of the effect of number of nozzle intakes on energy separation for Ranque-Hilsch vortex tube refrigerators based on Computational Fluid Dynamic (CFD)
Authors:
Adib Bazgir
B.Sc. Chemical engineering of Petroleum University of Technology
Dr. Mohammad Reza Khosravi Nikou
Department of Gas and Chemical engineering of Petroleum University of Technology

3. Overview:
Introduction
Literature Review
Objectives
References

4. Introduction : Introduction Literature Review Objectives References
Ranque-Hilsch vortex tube (RHVT) simply called as vortex tube:
It is a simple device with no moving parts.
It will convert a pressurized gas of homogeneous temperature in two streams of different temperatures, one warmer than the inlet and one cooler simultaneously.
Vortex tubes are generally classified as two types based on the cold exit position; counter-flow vortex tubes and parallel-flow vortex tubes.
Vortex tubes have widely been used in various applications, including heating and cooling, drying gases, gas liquefaction, separation of gas mixture, etc.

6. Different types of vortex tube:
Introduction
Literature Review
Objectives
References
In counter-flow vortex tubes, the cold fluid outlet is placed on the opposite end of the hot fluid outlet. In this paper, counter-flow geometry has been chosen.
In parallel-vortex tubes, the cold and hot fluid outlets are located at the same end.
a vortex tube mainly consists of one or more inlet nozzles, a vortex chamber, a cold orifice and a control valve that is located at the hot end.
Vortex tube refrigerator has many advantages over the conventional commercial refrigeration devices such as: simplicity, durability, smallness or lightness of weight, low cost, no need of electricity or chemicals, adjustability of temperature and more environmentally friendly.

7. Introduction
Literature Review
Objectives
References

8. Literature Review: Introduction Literature Review Objectives
References
1) Owing to the attractive advantages of the vortex tube, scientists have utilized various experimental, analytical and numerical analysis to study the transport phenomena in vortex tube science its discovery by Ranque in 1933.
2) Several experimental works have been indicated for the investigation of the effects of geometric characteristics such as vortex generator, length of main tube and cold orifice diameter on temperature separation and refrigeration capacity.
3) Due to limitation of the experimental work, some efforts have been made to successfully utilize computational fluid dynamic (CFD) to find numerical simulations for explanation the fundamental principle behind the energy separation within the vortex tube.

9. Introduction Literature Review Objectives References
Frohlingsdrof and Unger by using CFX code along with the k-ԑ model studied fluid flow and energy separation in a vortex tube.
Aljuwayhel and Nellis conducted a two dimensional axisymmetric CFD model to investigate the vortex tube energy separation mechanism and their results proved that their numerical model could predict the temperature separation successfully.
Behera et al. presented a three-dimensional CFD model for analysis of energy separation using the STAR-CD-Software with the RNG k-ԑ turbulence model.
Introduction
Literature Review
Objectives
References
(Frohlingsdrof and Unger ,1999)
(Aljuwayhel and Nellis ,2005)
(Behera et al. ,2008)

10. Introduction Literature Review Objectives References
(Eiamsa-ard and Promvonge , )
Eiamsa-ard and Promvonge carried out a numerical simulation to examine phenomena of the flow field and energy separation inside vortex tube flows.
Sky and Nellis conducted a similar research as Aljuwayhel and Nellis.
Kazantseva and Piralishvili simulated the swirling flow using software CFX-TASK.
Faruk and Farouk used large eddy simulation to obtain the energy separation inside vortex tube. They compared the predicated results with the published experimental results of Sky and Nellis.
(Sky and Nellis ,2006)
(Kazantseva and Piralishvili ,2005)
(Faruk and Farouk ,2007)

11. Introduction Literature Review Objectives References
(Pouroria and Zangooee ,2012)
Pouroria and Zangooee studied on the performance of a vortex tube refrigerator with a divergent hot-tube based on a two dimensional axis-symmetrical model.
Bovand and Valipour studied the performance of a vortex tube refrigerator with curved hot-tube based on a three -dimensional and utilizes the RNG k-ԑ turbulence model for determining the flow and temperature fields.
(Bovand and Valipour,2014)

12. Objectives of this project:
Introduction
Literature Review
Objectives
References
BOUNDARY CONDITIONS AND MODEL VALIDATION
1) The inlet is defined as pressure inlet, at which the total inlet pressure and temperature are specified for this study, the absolute total inlet pressure and temperature of the compressed air is assumed to vary in range of 0.3 to 0.7 MPa and 300 K.
2) The cold and hot fluid outlets are regarded as the pressure outlet condition; the pressure loss ratio is changed by changing both of the total cold and hot pressure outlet. Both absolute total pressure of hot and cold outlets are varied in the range of 0.01 to 0.25 MPa to adjust the pressure loss ratio and the total temperature.
3) The density based, implicit solver is used to solve the governing equations. Third-order MUSCL scheme is used for the convective terms in the momentum, energy and to ignore the displacement terms, QUICK scheme is used for turbulence equations . The under-relaxation is used in all cases for dependent variables.

13. Introduction Literature Review Objectives References
4) The temperature separation inside the vortex tube is a direct result of pressure loss ratio, and the bigger the pressure loss ratio, the larger the energy separation is. It can be also seen from Figure below that the numerical and experimental results of Liu et al. and present three - dimensional simulation agree each other well, which confirms further the reliability of our numerical model and solution method.
Introduction
Literature Review
Objectives
References

14. RESULTS AND DISCUSSIONS
Temperature distributions of vortex tubes with two, four and six inlet nozzles at Pin = 0.3 MPa, Pc = 0.08 MPa and Ph = 0.18 MPa are shown in Figure below.
Introduction
Literature Review
Objectives
References

15. Introduction Literature Review Objectives References
velocity distribution vectors of vortex tubes with two, four and six inlet nozzles at Pin = 0.3 MPa, Pc = 0.08 MPa and Ph = 0.18 MPa are shown in Figure below.
Introduction
Literature Review
Objectives
References

16. Introduction Literature Review Objectives References
The turbulence kinetic energy of vortex tubes with two, four and six inlet nozzles are shown in Figure below.
Introduction
Literature Review
Objectives
References

17. Introduction Literature Review Objectives References
To compare the temperature separation of different vortex tubes, the diagram of temperature distribution along the axial center line and radial direction at the middle of vortex tubes are shown in Figure below.

18. CONCLUSIONS Introduction Literature Review Objectives References
Temperature separation phenomenon inside vortex tube is investigated with the help of software Ansys Fluent The geometry of the model was created in software Gambit then the mesh study of three - dimensional model was done. One of the parameters can promote performance of vortex tube is the number of inlet nozzles. The major results of this research paper can be summarized as follows:
⦁ By increasing the number of inlet nozzles, the area surface of each nozzle decreases then this can lead to increase in magnitude of tangential velocity inside vortex tube. Consequently, by increasing tangential velocity, the more temperature separation will occur.
⦁ According to the major application of vortex tube in temperature separation phenomenon, when the flow inside vortex tube is turbulent especially at critical zone like inlet, the performance of this device will decrease and vice versa.
Introduction
Literature Review
Objectives
References

19. References: Introduction Literature Review Objectives References
1. Eiamsa-ard, S., and Promvonge, P., "Review of Ranque –Hilsch effects in vortex tubes," Renewable and sustainable energy reviews, 12(7), (2008).
2. Pouraria, H., and Zangooee, M., "Numerical investigation of vortex tube refrigerator with a divergent hot tube," Energy Procedia, 14, (2012).
3. Khodorkov, I., Poshernev, N., and Zhidkov, M., "The vortex tube - a universal device for heating, cooling, cleaning, and drying gases and separating gas mixtures," Chemical and Petroleum Engineering, 39(7-8), (2003).
4. Van Patten, R., and Gaudio, R., "Vortex tube as a thermal protective device," Aerospace medicine, 40(3), (1969).
5. KONZEN, R. B., "Gas-Vapor Separation in a Ranque-Hilsch Vortex Tube," The American Industrial Hygiene Association Journal, 32(12), (1971).

20. Introduction Literature Review Objectives References
6. Williams, A., "The cooling of methane with vortex tubes," Journal of Mechanical Engineering Science, 13(6), (1971).
7. Lucca-Negro, O., and O'doherty, T., "Vortex breakdown: a review," Progress in energy and combustion science, 27(4), (2001).
8. Park, W.-G., "Hassan Pouraria," THERMAL SCIENCE, 18(4), (2014).
9. Riu, K.-J., Kim, J.-s., and Choi, I.-S., "Experimental investigation on dust separation characteristics of a vortex tube," JSME International Journal Series B Fluids and Thermal Engineering, 47(1), (2004).
10. Aydın, O., Markal, B., and Avcı, M., "A new vortex generator geometry for a counter-flow Ranque - Hilsch vortex tube," Applied Thermal Engineering, 30(16), (2010).

21. Introduction Literature Review Objectives References
11. Saidi, M., and Valipour, M., "Experimental modeling of vortex tube refrigerator," Applied thermal engineering, 23(15), (2003).
12. Valipour, M. S., and Niazi, N., "Experimental modeling of a curved Ranque - Hilsch vortex tube refrigerator," International journal of refrigeration, 34(4), (2011).
13. Fröhlingsdorf, W., and Unger, H., "Numerical investigations of the compressible flow and the energy separation in the Ranque -Hilsch vortex tube," International Journal of Heat and Mass Transfer, 42(3), (1999).
14. Aljuwayhel, N., Nellis, G., and Klein, S., "Parametric and internal study of the vortex tube using a CFD model," International journal of refrigeration, 28(3), (2005).
15. Behera, U., Paul, P., Kasthurirengan, S., Karunanithi, R., Ram, S., Dinesh, K., and Jacob, S., "CFD analysis and experimental investigations towards optimizing the parameters of Ranque - Hilsch vortex tube," International Journal of Heat and Mass Transfer, 48(10), (2005).

22. Introduction Literature Review Objectives References
16. Behera, U., Paul, P., Dinesh, K., and Jacob, S., "Numerical investigations on flow behaviour and energy separation in Ranque - Hilsch vortex tube," International Journal of Heat and Mass Transfer, 51(25), (2008).
17. Eiamsa-ard, S., and Promvonge, P., "Numerical investigation of the thermal separation in a Ranque - Hilsch vortex tube," International Journal of Heat and Mass Transfer, 50(5), (2007).
18. Eiamsa-ard, S., and Promvonge, P., "Numerical simulation of flow field and temperature separation in a vortex tube," International Communications in Heat and Mass Transfer, 35(8), (2008).
19. Skye, H., Nellis, G., and Klein, S., "Comparison of CFD analysis to empirical data in a commercial vortex tube," International Journal of Refrigeration, 29(1), (2006).
20. Kazantseva, O., Piralishvili, S. A., and Fuzeeva, A., "Numerical simulation of swirling flows in vortex tubes," High Temperature, 43(4), (2005).

23. Introduction Literature Review Objectives References
21. Farouk, T., and Farouk, B., "Large eddy simulations of the flow field and temperature separation in the Ranque - Hilsch vortex tube," International Journal of Heat and Mass Transfer, 50(23), (2007).
22. Bovand, M., Valipour, M. S., Dincer, K., and Tamayol, A., "Numerical analysis of the curvature effects on Ranque - Hilsch vortex tube refrigerators," Applied Thermal Engineering, 65(1), (2014).
23. Fluent, F., "6.3 user’s guide," Fluent Inc, (2006).
24. Liu, X., and Liu, Z., "Investigation of the energy separation effect and flow mechanism inside a vortex tube," Applied Thermal Engineering, 67(1), (2014).