Three-Dimensional Simulation of Fluid Flow and Energy Separation Inside a Vortex Tube

2014 ◽  
Vol 28 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Seyed Ehsan Rafiee ◽  
Masoud Rahimi
Author(s):  
S. Shahsavari ◽  
M. B. Shafii ◽  
M. H. Saidi

Thermopneumatic micropump is one type of positive displacement micropump, which has many applications due to its relatively large stroke volume, low working voltage, and simple fabrication in microscale. In this paper, a numerical study of heat transfer and fluid flow in a valveless thermopneumatically driven micropump is presented. For rectifying the bidirectional flow, a nozzle and a diffuser are used as the inlet and outlet channels of the chamber. Since the fluid flow is induced by the motion of a diaphragm, the numerical simulation includes fluid structure interaction, which requires applying a dynamic mesh. The domain of solution is divided into two sections; the actuator unit, which contains the secondary fluid, and the main chamber through which the working fluid is passing. The temperature distribution, the pressure variations, and the center deflection of the diaphragm are obtained. In order to validate the model, the numerical results are compared with some experimental data, which shows fair consistency. According to the results of the three dimensional simulation, the rectification efficiency for the nozzle and diffuser channels depends on the frequency.


2013 ◽  
Vol 397-400 ◽  
pp. 205-208
Author(s):  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Shi Long Liu ◽  
Wen Long Sun

This paper aims to investigate fixed composition natural gases including N2, CH4 and C2H4 energy separation effect in vortex tube. Energy separation phenomena of those gases were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of natural gases in fixed inlet boundary conditions were simulated. The results main factors were found that affect the energy separation with cold mass fraction being 0.7 and pressure drop ratio being 3.90. At the same time, this paper has illustrated the effects and tendencies of energy separation with gases in the tube under the same cold mass flow fraction and cold pressure ratio. The results show mixture gases total temperature difference effect is unchanged varied with the cold mass fraction; CH4% has no effect on the vortex cold end temperature separation, but varied of CH4% has an influence in total temperature and hot end separation effect; total temperature separation effect of CH4% was divided into two sections, one is0%-80%, and the other 80%-100%.


2017 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Kiran Dattatraya Devade ◽  
Ashok T. Pise ◽  
Atul R. Urade

The vortex tube is an energy separation device that separates compressed gas stream into a low and a high temperature stream. Present work reports the flow behavior inside the vortex tube for different commonly used fluids with varied properties like Air, He, N2, CO2 and NH3. Flow behavior investigation for three-dimensional short straight-diverging vortex tube is done with CFD code (ANSYS 16.0). Different turbulent models, standard k-epsilon, Realizable k-epsilon and RNG k-epsilon are tested. Realizable k-epsilon model was then used for analysis. Flow behavior of gases with varied multi-atomic number is analyzed and compared with literature. The effect on temperature for N2 is found to be better, followed by He, CO2, Air and NH3. Energy separation for N2 is 46 % higher than all other gases. Energy separation and flow behavior inside vortex tube is analyzed and compared with literature.


2012 ◽  
Vol 22 (12) ◽  
pp. 3081-3086 ◽  
Author(s):  
Bao-hua YANG ◽  
Ai-xiang WU ◽  
Chun-lai WANG ◽  
Wen-xin NIU ◽  
Jin-zhi LIU

2012 ◽  
Vol 16 (1) ◽  
pp. 151-166 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Hassan Zadeh ◽  
Omid Moutaby ◽  
Abdolreza Bramo

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-? 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.


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