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.

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.

Three-Dimensional Numerical Analysis for Bolted Flange Joints Considering Effect of Creep

2018 ◽  
Author(s):  
Lewen Bi ◽  
Lanzhu Zhang
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Numerical Analysis ◽  
Yield Strength ◽  
Room Temperature ◽  
Three Dimensional ◽  
Short Term ◽  
Flange Connection ◽  
Petroleum Chemical ◽  
Bolted Flange

Bolted flange joints are widely used in petroleum, chemical, nuclear and power industries, etc. With more and more devices are used at high temperature, the performance of flange connections becomes more complex, especially with creep of different components in flange connection. At elevated temperature, with the loss of bolt force and gasket force due to creep, the joints are prone to leak. Based on this, this paper analyzed the relaxation of bolt force at elevated temperature due to creep of bolt, flange and gasket separately and simultaneously. Besides, the influence of different initial installation stress of bolts was also studied. The results showed bolted flange joints relaxed due to gasket creep during early short term service. However, contribution of bolt and flange creep became more and more significant with the extension of time. With considering the creep of bolt, flange and gasket simultaneously, 50% to 60% of the bolt material yield strength at room temperature was recommended as the bolt initial installation stress for the joint case studied in this paper.

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%.

Numerical Analysis of Three-Dimensional Flow in an Industry-Size Hydrothermal Autoclave Subjected to Non-Uniform Heating

2002 ◽  
Author(s):  
Hongmin Li ◽  
Guo-Xiang Wang ◽  
Edward A. Evans
Keyword(s):  
High Temperature ◽  
Numerical Analysis ◽  
Three Dimensional ◽  
Hydrothermal Growth ◽  
Chamber Wall ◽  
Heating Condition ◽  
Uniform Heating ◽  
Three Dimensional Flow ◽  
Growth Environment ◽  
Dimensional Flow

Hydrothermal growth is an important industrial process to produce piezoelectric crystals such as quartz. It takes place in a cylindrical container called an autoclave, which is filled with aqueous solution at a high temperature and a high pressure. The high temperature growth condition is maintained through electrical resistors on the outer surface of an autoclave. In practice there is a non-uniform heating condition in the circumferential direction. Many theoretical and numerical studies, however, assume an axisymmetric heating condition. This paper presents a numerical analysis of the three-dimensional heat transfer and fluid flow in hydrothermal growth due to such non-uniform heating. The analysis is based on an industry-size autoclave with an aspect ratio of 10. The non-uniform heating is introduced on the surface of both the lower dissolving chamber and the upper growing chamber of an autoclave with and without a baffle at the middle height. The flow and isotherm patterns were obtained with the temperature difference between the two chambers kept at 10 °C. The circumferentially non-uniform temperature has dramatic effects on the three-dimensional flow and therefore the temperature distribution in the autoclave. When the dissolving chamber is subjected to circumferentially non-uniform heating, a baffle is essential to create a uniform growth environment in the growing chamber. To obtain high quality single crystals, however, the temperature control on the growing chamber wall is more important than that on the dissolving chamber wall.

scholarly journals Experimental Investigation of Vortex-Tube Streamwise-Vorticity Characteristics and Interaction Effects with a Finite-Aspect-Ratio Wing

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 122
Author(s):  
Bailey Carlson ◽  
Al Habib Ullah ◽  
Jordi Estevadeordal
Keyword(s):  
Wind Tunnel ◽  
Aspect Ratio ◽  
Vortex Tube ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Streamwise Vortex ◽  
Streamwise Vorticity ◽  
Flow Measurements ◽  
Freestream Velocity ◽  
Naca0012 Airfoil

An experimental study is conducted to analyze a streamwise-oriented vortex and investigate the unsteady interaction with a finite-aspect-ratio wing. A pressurized vortex tube is used to generate streamwise vortices in a wind tunnel and the resulting flow behavior is analyzed. The vortex tube, operated at various pressures, yields flows that evolve downstream under several freestream wind tunnel speeds. Flow measurements are performed using two- and three- dimensional (2D and 3D) particle image velocimetry to observe vortices and their freestream interactions from which velocity and vorticity data are comparatively analyzed. Results indicate that vortex velocity greater than freestream flow velocity is a primary factor in maintaining vortex structures further downstream, while increased supply pressure and reduced freestream velocity also reduce vortex dissipation rate. The generated streamwise-oriented vortex is also impinged on a finite-aspect-ratio airfoil wing with a cross-section of standard NACA0012 airfoil. The wingtip-aligned vortex is shown to investigate the interaction of the streamwise vortex and the wingtip vortex region. The results indicate that the vorticity at the high vortex-tube pressure has a significant effect on the boundary layer of airfoil.

Application Analysis of Vortex TubeTemperature Difference Phenomenon in High-Temperature Cyclone Separator

2010 ◽  
Vol 42 ◽  
pp. 351-354
Author(s):  
Wei Sheng ◽  
Xiu Fang Liu ◽  
Hua Wang ◽  
Zhi Wei Gao ◽  
Ru Chao Liu
Keyword(s):  
High Temperature ◽  
Temperature Difference ◽  
Vortex Tube ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Cooling Effect ◽  
Cyclone Separator ◽  
Compressed Gas ◽  
Difference Effect ◽  
High Temperature Gas

The compressed gas for ambient temperature in vortex tube can be separated into two streams of different temperature gas, which phenomenon is unapparent for non-compressed gas. However, for non-compressed high-temperature gas, it can produce temperature difference of more than 20°C in vortex tube, which has been ignored by researchers. In this paper, basic principle of temperature difference effect in vortex tube is described firstly, and cooling effect produced by different inlet temperature in the condition of low pressure ratio is analyzed, which results that obvious cooling effect can still be produced for high temperature and low pressure ratio. Combined with factual operation conditions of cyclone separator for circulating fluidized bed (CFB) boiler, a design and renovation method of cyclone separator is proposed firstly according to temperature difference effect principle of high-temperature gas in vortex tube. According to the analysis, the separation efficiency and boiler performance will be enhanced by using temperature difference effect in vortex tube to design and reconstruct the existing cyclone separator.

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