scholarly journals CFD simulation of length to diameter ratio effects on the energy separation in a vortex tube

2011 ◽  
Vol 15 (3) ◽  
pp. 833-848 ◽  
Author(s):  
Reza Bramo ◽  
Nader Pourmahmoud
Keyword(s):  
Stagnation Point ◽  
Cfd Simulation ◽  
Vortex Tube ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Diameter Ratio ◽  
Tube Length ◽  
Energy Separation ◽  
Computational Fluid Dynamics Analysis ◽  
Length To Diameter Ratio

The objective of the present computational fluid dynamics analysis is an attempt to investigate the effect of length to diameter ratio on the fluid flow characteristics and energy separation phenomenon inside the Ranque-Hilsch vortex tube. In this numerical study, performance of Ranque-Hilsch vortex tubes (RHVT), with length to diameter ratios (L/D) of 8, 9.3, 10.5, 20.2, 30.7 and 35 with six straight nozzles was investigated. It includes generating better understanding of the effects of the stagnation point location on the performance of RHVT. It was found that the best performance was obtained when the ratio of vortex tube length to the diameter was 9.3 and also fort this case the stagnation point was found to be the farthest from the inlet. The results show that the closer distance to the hot end is produced the larger magnitude of the temperature difference. Computed results show good agreement with published experimental results.

scholarly journals The second law analysis of natural gas behavior within a vortex tube

2013 ◽  
Vol 17 (4) ◽  
pp. 1079-1092 ◽  
Author(s):  
Mahyar Kargaran ◽  
A. Arabkoohsar ◽  
S.J. Hagighat-Hosini ◽  
V. Farzaneh-Kord ◽  
Mahmood Farzaneh-Gord
Keyword(s):  
Natural Gas ◽  
Entropy Generation ◽  
Vortex Tube ◽  
Tube Length ◽  
Orifice Diameter ◽  
Working Fluid ◽  
Energy Separation ◽  
Second Law ◽  
Gas Streams ◽  
Mass Fractions

Vortex tube is a simple device without a moving part which is capable of separating hot and cold gas streams from a higher pressure inlet gas stream. The mechanism of energy separation has been investigated by several scientists and second law approach has emerged as an important tool for optimizing the vortex tube performance. Here, a thermodynamic model has been used to investigate vortex tube energy separation. Further, a method has been proposed for optimizing the vortex tube based on the rate of entropy generation obtained from experiments. Also, an experimental study has been carried out to investigate the effects of the hot tube length and cold orifice diameter on entropy generation within a vortex tube with natural gas as working fluid. A comparison has been made between air and natural gas as working fluids. The results show that the longest tube generates lowest entropy for NG. For air, it is middle tube which generates lowest entropy. Integration of entropy generation for all available cold mass fractions unveiled that an optimized value for hot tube length and cold orifice diameter is exist.

scholarly journals Computational fluid dynamics analysis of the influence of injection nozzle lateral outflow on the performance of Ranque-Hilsch vortex tube

2014 ◽  
Vol 18 (4) ◽  
pp. 1191-1201 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Alireza Izadi ◽  
Amir Hassanzadeh ◽  
Ashkan Jahangiramini
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Vortex Tube ◽  
Operating Conditions ◽  
Energy Separation ◽  
Physical Parameters ◽  
Dynamics Analysis ◽  
Computational Domain ◽  
Computational Fluid Dynamics Analysis

In this article computational fluid dynamics analysis of a three-dimensional compressible and turbulent flow has been carried out through a vortex tube. The standard k-? turbulence model is utilized in order to simulate an axisymmetric computational domain. The numerical simulation has focused on the energy separation and flow field patterns of a somewhat nonconventional vortex tube, which is on the basis of creating an external hole at the end of each nozzle. According to the selected nozzles geometry, some of unfavorable phenomena such as shock wave, high pressure regions and appearing of unsymmetrical rotating flow patterns in the vortex chamber would be recovered significantly. In this way the physical parameters of flow field are derived under different both inlet mass flow rates and outlet pressures of nozzles hole (OPH). The results show that increasing OPH value enhanced the cooling capacity of machine in the most of operating conditions.

Experimental and Numerical Investigation on Effect of Convergent Angle and Cold Orifice Diameter on Thermal Performance of Convergent Vortex Tube

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Seyed Ehsan Rafiee ◽  
M. M. Sadeghiazad ◽  
Nasser Mostafavinia
Keyword(s):  
Numerical Investigation ◽  
Cfd Simulation ◽  
Vortex Tube ◽  
Orifice Diameter ◽  
Energy Separation ◽  
Separation Procedure ◽  
Laboratory Setup ◽  
Air Temperatures ◽  
Invaluable Tool ◽  
Air Separator

The vortex tube (VT) air separator is an invaluable tool which has the ability to separate a high-pressure fluid into the cold and hot fluid streams. The hot tube is a main part of the air separator VT which the energy separation procedure happens along this part. This research has been done to analyze the effect of the convergent angle and cold orifice diameter on the thermal efficiency of a convergent vortex tube (CVT). The CVT is linked to an air pipeline with the fixed pressure of 6.5 bar. The convergent hot tube angle is varied over the range of 1 deg to 9 deg. The consideration of the main angle effect denotes that the highest thermal ability could be achieved at β = 5 deg. The laboratory setup results show this subject that the optimization of the hot tube convergent angle elevates the cooling and heating effectiveness around 32.03% and 26.21%, respectively. Experiments denoted that both cooling capability and heating effectiveness reach the highest magnitudes when the DCold is around 9 mm. After these two stages, the optimized CVT was capable of decreasing and rising air temperatures at the cold and the hot sides up to 9.05 K (42.89%) and 10.48 K (44.74%), respectively. A computational fluid dynamics (CFD) model was employed to predict the performance of the air flow inside the CVT. The numerical investigation was done by full 3D steady-state CFD-simulation using fluent6.3.26. The results show that the agreement between computation predictions and laboratory measurements is fairly good.

Numerical study of energy separation in a vortex tube with different RANS models

2011 ◽  
Vol 50 (12) ◽  
pp. 2377-2385 ◽  
Author(s):  
Mohammed Baghdad ◽  
Ahmed Ouadha ◽  
Omar Imine ◽  
Yacine Addad
Keyword(s):  
Vortex Tube ◽  
Numerical Study ◽  
Energy Separation ◽  
Rans Models

NUMERICAL RESEARCH ON A SPECIAL FLUID PHENOMENON: RANQUE-HILSCH EFFECT

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1723-1726 ◽  
Author(s):  
J. Y. LIU ◽  
M. Q. GONG ◽  
Y. ZHANG ◽  
H. HONG ◽  
J. F. WU
Keyword(s):  
High Speed ◽  
Numerical Solutions ◽  
Vortex Tube ◽  
Flow Characteristics ◽  
Temperature Fields ◽  
Energy Separation ◽  
Separation Effect ◽  
Speed Flow ◽  
Flow Features ◽  
Numerical Research

An application of CFD model for the simulation of a strongly swirling and high speed flow in the vortex tube is presented in this paper. A partly modified standard K-ε turbulent model has been used to investigate the flow characteristics and energy separation effect in the vortex tube. It is found that there is an obvious energy separation effect in the vortex tube and the numerical solutions of the flow and temperature fields agree well with the experiments. More detailed flow features are obtained by the CFD calculation. Based on the validated numerical model, the influence of the cold flow fraction on the energy separation effect is also investigated and compared with experimental results.

scholarly journals Computational design optimization of industrial single piece ball valve to enhance the flow performance

2021 ◽  
Vol 2070 (1) ◽  
pp. 012197
Author(s):  
Ravichandra Rangappa ◽  
BRN Murthy ◽  
Avinash Porali ◽  
S Rajesha ◽  
N Natarajan
Keyword(s):  
Design Optimization ◽  
Cfd Simulation ◽  
Flow Characteristics ◽  
Computational Design ◽  
Ball Valve ◽  
Valve Body ◽  
Single Piece ◽  
Computational Fluid Dynamics Analysis ◽  
Flow Through ◽  
And Performance

Abstract The characteristics of flow through the fluid flow system largely depends on the control valves and their performance. Ball valves are one among the major valves widely used in various industries due to their simple construction and ease of manufacturing. Thus investigating flow characteristics of these valves is most essential to minimize the losses due to friction and cavitation caused within the valve body. The main objective of the current work is to carry out the computational fluid dynamics analysis using Ansys® Fluent® as solver and Solidworks® as 3D modelling tools to investigate the flow patterns through the single piece ball valve to determine the various flow characteristic and there by suggest design optimization for improved flow rate and performance. Various designs of ball valve such as BVD1, BVD2 and BVD3 were tested through CFD simulation. The simulation results reveals that BVD1 and BVD2 are failed in bidirectional flow characteristics. However BVD3 shows the significant improvement in all the flow characteristics.

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