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.

Investigations of Energy Separation Effect in Vortex Tube for Natural Gases

2013 ◽  
Vol 397-400 ◽  
pp. 205-208
Author(s):  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Shi Long Liu ◽  
Wen Long Sun
Keyword(s):  
Mass Fraction ◽  
Vortex Tube ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Energy Separation ◽  
Separation Effect ◽  
Natural Gases ◽  
Temperature Separation ◽  
Total Temperature ◽  
Cold Mass

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%.

Investigations of Energy Separation Effect in Vortex Tube for Real Gases

2013 ◽  
Vol 724-725 ◽  
pp. 1293-1300
Author(s):  
Jing Tang ◽  
Wen Chuan Wang ◽  
Xiang Jun Fang ◽  
Shi Long Liu ◽  
Wen Long Sun
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Vortex Tube ◽  
Ideal Gas ◽  
Energy Separation ◽  
Separation Effect ◽  
Real Gas ◽  
Real Gas Effect ◽  
Effect Difference ◽  
Gas Effect

This paper aims to investigate real gases energy separation effect such as real natural gas, CH4 and C2H4 in vortex tube. Energy separation phenomena of real natural gas (RNG) were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of ideal natural gas (ING), or RNG in low and high pressure were simulated. The results main factors were found that affect the separation effect. At the same time, this paper has illustrated the effect and tendency of energy separation with real gas in the tube under the same cold mass fraction and pressure ratio. The results show low pressure ideal gas and real gas energy separation effect difference about 3-4°C, the real gas effect is not obvious; High pressure real natural gas (HPRNG) and ideal gas (HPING) effect difference is 13-14°C, the real gas effect is obvious; CH4 (LRCH4) and C2H4 (HRC2H4) energy separation effect is obvious and effect of real gas is generated.

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.

High speed flow characteristics in gun tunnel

2012 ◽  
Author(s):  
Diyar I. Ahmed ◽  
M. Z. Yusoff ◽  
Al-Falahi Amir ◽  
S. Kasolang
Keyword(s):  
High Speed ◽  
Flow Characteristics ◽  
High Speed Flow ◽  
Speed Flow

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 Experiment on the Effect of Superficial Gas-Liquid Velocities on Slug Flow-Induced Vibration in an Inclined Sagged Riser

2020 ◽  
Author(s):  
Bowen Ma ◽  
Narakorn Srinil ◽  
Hongjun Zhu ◽  
Yue Gao
Keyword(s):  
Slug Flow ◽  
High Speed ◽  
Liquid Velocity ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Small Scale ◽  
Flow Induced Vibration ◽  
Pressure Transducers ◽  
Test Loop ◽  
Flow Features

Abstract Subsea liquid-gas flows conveyed through a flexible riser or pipeline may develop into various flow patterns including slug flow. In this study, the slug flow-induced vibration (SIV) of an inclined sagged riser conveying upward air-water flows is experimentally investigated. A small-scale experiment is carried out in an air-water test loop with a section of a free-hanging catenary tube made of silica gel. Attention is placed on the effect of superficial gas and liquid velocities on SIV responses. Both pipe motions and flow patterns are recorded using non-intrusive high-speed cameras. Pressure variations are also measured at the pipe inlet and outlet by two pressure transducers. The SIV system is tested by employing different ratios of the superficial gas-liquid velocities. Occurrence of unstable slug flows is captured at the relatively high gas-to-liquid velocity ratios, leading to a large-amplitude SIV. Experimental results of the space-time varying riser responses and oscillation frequencies are reported together with the associated slug flow features. Depending on the gas-liquid superficial velocities, slug flow characteristics are observed to vary significantly. These entail an intermittent SIV with modulated amplitudes and frequencies along riser span, signalling a potential dynamic stress and fatigue-related concern. In all experimental cases, the riser responses are found to be multi-modal and dominated by the fundamental planar mode whereas an out-of-plane vibration is negligible. Experimental observations suggest the key interrelationships of the two-fluid flow conditions, the slug characteristics and the pipe dynamics. This finding is meaningful for a practical design of riser transporting internal multiphase flows.

scholarly journals High Speed Flow Characteristics in Gun Tunnel

2012 ◽  
Vol 41 ◽  
pp. 1787-1793 ◽  
Author(s):  
Diyar I. Ahmed ◽  
M.Z. Yusoff ◽  
Al-Falahi Amir ◽  
S. Kasolang
Keyword(s):  
High Speed ◽  
Flow Characteristics ◽  
High Speed Flow ◽  
Speed Flow
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