CFD analysis of energy separation of vortex tube employing different gases, turbulence models and discretisation schemes

2014 ◽  
Vol 78 ◽  
pp. 360-370 ◽  
Author(s):  
H.R. Thakare ◽  
A.D. Parekh
Keyword(s):  
Vortex Tube ◽  
Turbulence Models ◽  
Energy Separation ◽  
Cfd Analysis ◽  
Different Gases

scholarly journals CFD Analysis of Energy Separation in Ranque-Hilsch Vortex Tube at Cryogenic Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
T. Dutta ◽  
K. P. Sinhamahapatra ◽  
S. S. Bandyopadhyay
Keyword(s):  
Cryogenic Temperature ◽  
Vortex Tube ◽  
Atmospheric Temperature ◽  
Working Fluid ◽  
Energy Separation ◽  
Cfd Analysis ◽  
Sensible Heat ◽  
Cfd Model ◽  
Parametric Sensitivity ◽  
Fluid Layers

Study of the energy separation phenomenon in vortex tube (VT) at cryogenic temperature (temperature range below 123 K) has become important because of the potential application of VT as in-flight air separator in air breathing propulsion. In the present study, a CFD model is used to simulate the energy separation phenomenon in VT with gaseous air at cryogenic temperature as working fluid. Energy separation at cryogenic temperature is found to be considerably less than that obtained at normal atmospheric temperature due to lower values of inlet enthalpy and velocity. Transfer of tangential shear work from inner to outer fluid layers is found to be the cause of energy separation. A parametric sensitivity analysis is carried out in order to optimize the energy separation at cryogenic temperature. Also, rates of energy transfer in the form of sensible heat and shear work in radial and axial directions are calculated to investigate the possible explanation of the variation of the hot and cold outlet temperatures with respect to various geometric and physical input parameters.

scholarly journals Numerical modeling of the effect of energy-separation in the ranque-hilsch tube

2020 ◽  
Vol 27 ◽  
pp. 00109
Author(s):  
Boris L. Ivanov ◽  
Bulat G. Ziganshin ◽  
Andrey V. Dmitriev ◽  
Maxim A. Lushnov ◽  
Manuel O. Binelo
Keyword(s):  
Gas Flow ◽  
Vortex Tube ◽  
Turbulence Models ◽  
Effect Of Temperature ◽  
Energy Separation ◽  
Hydrodynamic Characteristics ◽  
Two Phase ◽  
Cross Sectional ◽  
Model Calculations ◽  
Temperature Separation

Currently, there are a lot of applications of vortex technologies. The vortex effect is used in gasdynamic cold generators and vortex cooling chambers. Vortex devices are also used as dehumidifiers, separators, for cooling and heating hydraulic fluids, separating two-phase media, gas mixtures, evacuating, etc. Scientists study the applicability of vortex equipment for traditional and freeze-drying of agricultural products. However, the influence of geometric parameters of vortex devices on the productivity and energy efficiency of temperature separation of gas flows is poorly studied. Research aimed at finding opportunities and expanding the field of application of vortex tubes is an urgent task. The paper describes twodimensional and three-dimensional mathematical models of the swirling gas flow arising in a vortex tube. It presents results of its implementation in the Anсs-Fluent software package. Thermodynamic and hydrodynamic characteristics confirm the effect of temperature separation in a vortex tube. The dependences of temperature separation on the swirl angle and inlet pressure were obtained. For a two-dimensional vortex tube model, calculations were carried out using various turbulence models. The influence of the cross-sectional area at the hot gas flow outlet on temperature separation was studied.

scholarly journals Numerical Analysis of Flow Behavior in Vortex Tube for Different Gases

2017 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Kiran Dattatraya Devade ◽  
Ashok T. Pise ◽  
Atul R. Urade
Keyword(s):  
High Temperature ◽  
Numerical Analysis ◽  
Vortex Tube ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Energy Separation ◽  
Separation Device ◽  
Compressed Gas ◽  
Turbulent Models ◽  
Different Gases

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.

scholarly journals CFD analysis of helical nozzles effects on the energy separation in a vortex tube

2012 ◽  
Vol 16 (1) ◽  
pp. 151-166 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Hassan Zadeh ◽  
Omid Moutaby ◽  
Abdolreza Bramo
Keyword(s):  
Vortex Tube ◽  
Numerical Models ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Vortex Chamber ◽  
Energy Separation ◽  
Outlet Temperature ◽  
Computational Domain ◽  
Cfd Analysis ◽  
Swirl Velocity

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.

scholarly journals Experimental study and CFD analysis of energy separation in a counter flow vortex tube

2019 ◽  
pp. 418-418
Author(s):  
Lizan Zangana ◽  
Ramzi Barwari
Keyword(s):  
Mass Fraction ◽  
Vortex Tube ◽  
Coefficient Of Performance ◽  
Energy Separation ◽  
Outlet Temperature ◽  
Cfd Analysis ◽  
Counter Flow ◽  
Radial Profiles ◽  
Swirl Velocity ◽  
Flow Vortex

In this manuscript, both experimental and numerical investigations have been carried out to study the mechanism of separation energy and flow phenomena in the counter flow vortex tube. This manuscript presents a complete comparison between the experimental investigation and CFD analysis. The experimental model was manufactured with (total length of 104 mm and the inner diameter of 8 mm, and made of cast iron) tested under different inlet pressures (4, 5 and 6 bar). The thermal performance has been studied for hot and cold outlet temperature as a function of mass fraction ? (0.3- 0.8). Three-dimensional numerical modeling using the k-? model used with code (Fluent 6.3.26). Two types of velocity components are studied (axial and swirl). The results show any increase in both cold mass fraction and inlet pressure caused to increase ?Tc, and the maximum ?Tc value occurs at P = 6 bar. The coefficient of performance (COP) of two important factors in the vortex tube which are a heat pump and a refrigerator have been evaluated, which ranged from 0.25 to 0.74. A different axial location (Z/L = 0.2, 0.5, and 0.8) was modeled to evaluate swirl velocity and radial profiles, where the swirl velocity has the highest value. The maximum axial velocity is 93, where it occurs at the tube axis close to the inlet exit (Z/L=0.2). The results showed a good agreement for experimental and numerical analysis.

scholarly journals Numerical investigation on cooling performance of Ranque-Hilsch vortex tube

2014 ◽  
Vol 18 (4) ◽  
pp. 1173-1189 ◽  
Author(s):  
Hassan Pouraria ◽  
Warn-Gyu Park
Keyword(s):  
Vortex Tube ◽  
Cooling System ◽  
Flow Behavior ◽  
Temperature Drop ◽  
Turbulence Models ◽  
Peripheral Region ◽  
Energy Separation ◽  
Net Energy ◽  
Cooling Performance ◽  
Refrigeration Capacity

A Ranque-Hilsch vortex tube (RHVT) is a mechanical device that separates a high pressure gas stream into low pressure hot and cold streams. In this study, four different two equation turbulence models namely the standard k-?, RNG k-?, Realizable k-? and standard k-? models were compared to identify the appropriate turbulence model for studying the energy separation effect in a RHVT. Comparison between the numerical and experimental results indicates that the standard k-? model is better than other models in predicting the energy separation phenomenon. The distributions of temperature, pressure, and components of velocity have been obtained in order to understand the flow behavior inside the tube. The effect of cold outlet diameter on temperature drop and refrigeration capacity was studied. The effect of cold mass fraction on the movement of stagnation point and refrigeration capacity has been investigated. Moreover, the feasibility of improving the cooling performance of vortex tube using the cooling system was investigated. The present numerical results revealed that using the cooling system, the net energy transfer rate from cold inner region to the hot peripheral region increases, thereby improving the cooling performance of the device.

Investigations of Energy Separation Effect in Vortex Tube for Different Gases

2013 ◽  
Vol 724-725 ◽  
pp. 1227-1233
Author(s):  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Wen Long Sun ◽  
Qi Tai Eri ◽  
Shi Long Liu
Keyword(s):  
Heat Capacity ◽  
Natural Gas ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Vortex Tube ◽  
Energy Separation ◽  
Separation Effect ◽  
Polyatomic Gas ◽  
Different Gases ◽  
Monatomic Gas

The paper aims to investigate the energy separation effect of gases such as natural gas to vortex tube. Energy separation phenomena of different gases were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of natural gas, air, nitrogen, et al were simulated. The main factors that affect the energy separation were found. With cold mass fraction being 0.7 and pressure drop ratio being 3.90, the results show the effect can be divided into three intervals in terms of the freedom degrees. The first interval is filled with monatomic gas at 50°C to 60°C; the second diatomic gas at40°C to 50°C; and the third polyatomic gas at 0°C to 40°C. In monatomic gas and diatomic gas, the smaller the gas specific heat capacity is, the better effect will be. However, in polyatomic gas, bigger specific heat capacity ensures better energy separation.

Aerodynamic and thermal characteristics of a maxwell type vortex tube

2011 ◽  
Vol 1 (4) ◽  
Author(s):  
S. Rahman ◽  
A. Mujumdar
Keyword(s):  
Vortex Tube ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Turbulence Models ◽  
Computational Fluid Dynamic Simulation ◽  
Energy Separation ◽  
Numerical Predictions ◽  
Temperature Separation

AbstractA three-dimensional (3D) computational fluid dynamic simulation of a vortex tube is carried out to examine its flow and thermal characteristics. The aim of this work is to model the performance of the vortex tube and to capture the highly swirling compressible flow behavior inside the tube for an understanding of the well known temperature separation process. Simulations were carried out using the standard k-ɛ, k-omega, RNG k-ɛ and swirl RNG k-ɛk-ɛ turbulence models. An experimental setup was built and tested to validate the simulation results. The RNG k-ɛ turbulence model yielded better agreement between the numerical predictions and experimental data. This model captured well the essential features of the flow including formation of the outer vortex and the inner reverse vortex flow. Flow and geometric parameters that affect the flow behavior and energy separation are studied numerically. Effects of the inlet pressure, with and without an insert in the tube, are examined by numerical experiments.

Numerical Analysis of Hot Ends Length Effect on the Performance of Energy Separation in Vortex Tube

2013 ◽  
Vol 732-733 ◽  
pp. 120-126 ◽  
Author(s):  
Zhong Ye Wu ◽  
Xiang Jun Fang ◽  
Wen Long Sun
Keyword(s):  
Numerical Analysis ◽  
Vortex Tube ◽  
Fluid Dynamic ◽  
Computing Time ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Energy Separation ◽  
Straight Pipe ◽  
Length Effect ◽  
Sst Model

In this paper, effects of the vortex tube hot end lengths on the performance are studied, using a three-dimensional numerical fluid dynamic model. The hot end and cold end structure of vortex tube adapts the conical tube with the dilated side connecting a straight pipe. Structural mesh is employed. Different turbulence models are used, compared with experiment, considered of convergence and computing time, eventually, SST model is applied. In contrast to experimental data, numerical results are acceptable. By numerical analysis, it is observed that as the length of hot ends increases, the performance of energy separation increases significantly. However, while the length diameter ratio is more than 20, the performance does not increase any more. Even, it begins to decrease. Meanwhile, different hot end lengths flow is compared, and attemptable analysis is conducted to the flow phenomenon.

Sign in / Sign up

Export Citation Format

Share Document