Computational investigation of precessing vortex breakdown and energy separation in a Ranque–Hilsch vortex tube

2018 ◽  
Vol 85 ◽  
pp. 42-57 ◽  
Author(s):  
Xiangji Guo ◽  
Bo Zhang
Keyword(s):  
Vortex Tube ◽  
Vortex Breakdown ◽  
Energy Separation ◽  
Computational Investigation

Forced and Periodic Vortex Breakdown

1967 ◽  
Vol 89 (3) ◽  
pp. 609-615
Author(s):  
Turgut Sarpkaya
Keyword(s):  
Experimental Study ◽  
Opposite Direction ◽  
Vortex Tube ◽  
Vortex Breakdown ◽  
Swirling Flow ◽  
Typical Data ◽  
Circular Orifice ◽  
Pros And Cons

The results of an experimental study of the forced and periodic breakdown of a confined vortex rotating in the opposite direction are presented. The vortex tube consists of two chambers connected by a short conduit through streamlined transitions. The upstream end is closed by a plain wall, and a circular orifice is provided at the downstream end. The swirling flow and the breaker-vortex are generated by introducing varying proportions of air or water through tangential ports located near the upstream and downstream walls of the unit. The cases of single breakdown and periodic breakdown are explored and typical data are presented for each case. Finally, the pros and cons of the two existing transition theories are discussed.

Influence of flow parameters in the dual nozzle CO2-based vortex tube cooling system during turning of Ti-6Al-4V

2021 ◽  
pp. 095440622110574
Author(s):  
Khirod Mahapatro ◽  
P Vamsi Krishna
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Vortex Tube ◽  
Cooling System ◽  
Cutting Temperature ◽  
Nozzle Diameter ◽  
Energy Separation ◽  
Optimum Conditions ◽  
Dry Cutting ◽  
Input Variables

Dual nozzle vortex tube cooling system (VTCS) is developed to improve the machinability of Ti-6Al-4V where cold-compressed CO2 gas is used as a coolant. The cooling effect is produced by the process of energy separation in the vortex tube and the coolant is supplied into the machining zone to remove the generated heat in machining. In this study, the responses such as cutting force (Fz), cutting temperature (Tm), and surface roughness (Ra) are analyzed by considering coolant inlet pressure, cold fraction, and nozzle diameter as input variables. Further optimization is performed for the input variables using the genetic algorithm technique, and the results at optimum conditions are compared with those of dry cutting. From the results, lower cutting force is observed at lower coolant pressure and cold fraction and higher nozzle diameter. The cutting temperature is minimized by increasing coolant pressure and cold fraction and by decreasing nozzle diameter. A better surface finish is observed at high coolant pressure and cold fraction and lower nozzle diameters. It is observed from the response surface method (RSM) that the coolant pressure is most significantly affecting all the responses. At optimum conditions, the cutting temperature and surface roughness are 35.6% and 66.14%, respectively, lower than dry cutting due to the effective cooling and lubricating action of the CO2 gas, whereas cutting force observed under the VTCS is 18.6% higher than that of dry cutting because of the impulse force of the coolant VTCS and thermal softening of the workpiece in dry cutting.

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.

An Experimental Investigation of the Cold Mass Fraction, Nozzle Number, and Inlet Pressure Effects on Performance of Counter Flow Vortex Tube

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
Volkan Kırmacı ◽  
Onuralp Uluer
Keyword(s):  
Experimental Investigation ◽  
Mass Fraction ◽  
Vortex Tube ◽  
Plastic Material ◽  
Momentum Conservation ◽  
Pressure Effects ◽  
Inlet Pressure ◽  
Frictional Heat ◽  
Energy Separation ◽  
Cold Mass

This paper discusses the experimental investigation of vortex tube performance as it relates to cold mass fraction, inlet pressure, and nozzle number. The orifices have been made of the polyamide plastic material. Five different orifices, each with two, three, four, five and six nozzles, respectively, were manufactured and used during the test. The experiments have been conducted with each one of those orifices shown above, and the performance of the vortex tube has been tested with air inlet pressures varying from 150 kPa to 700 kPa with 50 kPa increments and the cold mass fractions of 0.5–0.7 with 0.02 increments. The energy separation has been investigated by use of the experimentally obtained data. The results of the experimental study have shown that the inlet pressure was the most effective parameter on heating and the cooling performance of the vortex tube. This occurs due to the higher angular velocities and angular momentum conservation inside the vortex tube. The higher the inlet pressure produces, the higher the angular velocity difference between the center flow and the peripheral flow in the tube. Furthermore, the higher velocity also means a higher frictional heat formation between the wall and the flow at the wall surface of the tube. This results in lower cold outlet temperatures and higher hot outlet temperatures.

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%.

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.

The dynamics of confined vortices

1982 ◽  
Vol 382 (1783) ◽  
pp. 335-360 ◽  
Keyword(s):  
Vortex Core ◽  
Axial Velocity ◽  
Vortex Tube ◽  
Vortex Breakdown ◽  
Laser Doppler Anemometer ◽  
Present Evidence ◽  
Cylindrical Vortex ◽  
Breakdown Phenomenon ◽  
Similarities And Differences ◽  
Independent Parameters

Referring to flow-visualization and laser-Doppler anemometer measurements of swirl and axial velocity profiles, we discuss the physics of the flow in a cylindrical vortex tube as various independent parameters are varied. Three main classes of flow occur, depending upon the location of a vortex jump within the vortex tube. We present evidence to suggest a connection between vortex breakdown and the criticality and stability of the vortex core upon which it occurs and attempt to reconcile the various explanations that have been proposed for the breakdown phenomenon. Similarities and differences between the present experiments and those of previous investigators are also pointed out. Finally, as an Appendix, we present the results of a hydraulic analogue of our vortex experiment.

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.

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.

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