Numerical Modelling of Turbulent Flow in Vortex Tube

2010 ◽  
Author(s):  
Hossein Khazaei ◽  
Iman Mirzaii ◽  
Ali reza Teymourtash
Keyword(s):  
Vortex Tube ◽  
Complex Structure ◽  
Small Diameter ◽  
Energy Separation ◽  
Geometrical Parameters ◽  
Turbulent Model ◽  
Cfd Model ◽  
Governing Equations ◽  
Temperature Separation ◽  
Structure Of Flow

In this paper, energy separation effect in a vortex tube has been investigated using a CFD model. The numerical simulation has been done due to the complex structure of flow. The governing equations have been solved by FLUENT™ code in 2D compressible and turbulent model. The effects of geometrical parameters have been investigated. The results have shown that the hot outlet size and its shape, does not affect the energy distribution in vortex tube and very small diameter will decrease the temperature separation.

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 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 INVESTIGATION OF THE EFFECTS OF GEOMETRICAL PARAMETERS ON THE VORTEX SEPARATION PHENOMENON INSIDE A RANQUE-HILSCH VORTEX TUBE USED AS AN AIR SEPARATOR IN A HELICOPTER’S ENGINE

Aviation ◽  
2018 ◽  
Vol 22 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Adib Bazgir ◽  
Nader Nabhani
Keyword(s):  
Vortex Tube ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Geometrical Parameters ◽  
Cfd Model ◽  
Steady State Condition ◽  
Axial Angle ◽  
Temperature Reduction ◽  
Vortex Separation

Air separators are fitted to helicopter engine intakes to remove potentially harmful dust from the influent air. Their use is necessary in desert environments to eliminate the risk of rapid engine wear and subsequent power deterioration. However, their employment is concomitant with an inherent loss in inlet pressure and, in some cases, auxiliary power. There are three main technologies: vortex tubes, barrier filters, and integrated inlet particle separators. In this work, a vortex tube is investigated numerically. The study was conducted on the number and axial angle of inlet nozzles. Two and three-dimensional models are investigated at a steady state condition then the standard k-ε turbulence model is utilised for determining the flow and temperature fields. The finite volume method base on a Computational Fluid Dynamic (CFD) model is verified through the comparison with experimental data and numerical results of a vortex tube, reported in literature sources. Increasing the number of inlet nozzles, increases the sensitivity of the temperature reduction and the highest possible temperature reduction can be obtained. A vortex tube with an axial angle inlet nozzle of yields better performance. The numerical simulation results indicated that the CFD model is capable of predicting the vortex separation phenomenon inside a Ranque-Hilsch vortex tube with different geometrical parameters.

Experimental Study of Carbon Dioxide Separation From Gas Mixture by Vortex Tube

2017 ◽  
Author(s):  
Younghyeon Kim ◽  
Jinwon Yun ◽  
Sangseok Yu
Keyword(s):  
Gas Separation ◽  
Carbon Capture ◽  
Vortex Tube ◽  
Vortex Generator ◽  
Co2 Concentration ◽  
Atmospheric Temperature ◽  
Energy Separation ◽  
Co2 Gas ◽  
Temperature Separation ◽  
Climate Treaty

Due to the global warming, climate treaty regulations and credits have been enhanced. As a result, the Carbon Capture & Storage (CCS) technologies have been emerged. In this study, it is presented that is separating the CO2 from Air by vortex generator. The vortex tube is a device to separate inlet gases to hotter and colder mixture than inlet by energy separation technology. In this study, the vortex tube is applied to CO2 gas separation from air that is investigated under atmospheric temperature. Prior to feasibility experiment, transient response shows that the temperature separation is settled down in 3000 seconds. Experimental parameters of gas separation are pressures and concentrations of CO2 that is mixed with air. Results show that CO2 gas separation is proportional to operating temperature. The percentage of CO2 gas separation is 7.4 % at 3barg and cold mass fraction of 0.6. The gas separation is also affected by inlet CO2 concentration.

CFD investigation of inlet pressure effects on the energy separation in a vortex tube with convergent nozzles

2015 ◽  
Vol 32 (5) ◽  
pp. 1323-1342 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Masoud Rashidzadeh ◽  
Amir Hassanzadeh
Keyword(s):  
Vortex Tube ◽  
Numerical Data ◽  
Cooling Capacity ◽  
Pressure Effects ◽  
Energy Separation ◽  
Physical Parameters ◽  
Geometrical Parameters ◽  
Gas Temperature ◽  
Convergence Angle ◽  
Content Type

Purpose – The purpose of this paper is to investigate the effect of convergent nozzles on the thermal separation inside a vortex tube, using a three-dimensional (3D) computational fluid dynamics (CFD) model as predicting tool. Design/methodology/approach – The 3D finite volume formulation with the standard k-ε turbulence model has been used to carry out all the computations. Six different nozzles for convergence angle have been utilized β=0, 2, 4, 6, 8 and 10°. All other geometrical parameters were considered fixed at the experimental condition, i.e. main tube and chamber sizes and 294.2 K of gas temperature at inlets. Findings – The numerical results present that there is an optimum convergence angle for obtaining the highest efficiency and β=2° is the optimal candidate under the simulations. It can be pointed that, some numerical data are validated by the available experimental results which show good agreement. Practical implications – It is a useful and simple design of nozzle injectors to achieve the maximum cooling capacity. Originality/value – In the work with assuming the advantages of using convergent nozzles on the energy separation and their considerable role on the creation of maximum cooling capacity of machine, the shape of nozzles was concentrated. This research believes that choosing an appropriate convergence angle is one of the important physical parameters. So far, an effective investigation toward the optimization of convergent nozzles has not been done but the importance of this subject can be regarded as an interesting research theme; so that the machine would operate in the way that the maximum cooling effect or the maximum refrigeration capacity is provided.

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.

Influence of Marine Propeller Geometry on Turbulence Model Selection for CFD Simulations

2021 ◽  
Vol 55 (2) ◽  
pp. 150-164
Author(s):  
Mohamed R. Shouman ◽  
Mohamed M. Helal
Keyword(s):  
Turbulent Flows ◽  
Small Diameter ◽  
Turbulence Models ◽  
Dynamics Simulation ◽  
Geometrical Parameters ◽  
Test Case ◽  
Transition Model ◽  
Transient Flows ◽  
Marine Propellers ◽  
Numerical Predictions

Abstract One of the big challenges yet to be addressed in the numerical simulation of wetted flow over marine propellers is the influence of propellers' geometry on the selection of turbulence models. Since the Reynolds number is a function of the geometrical parameters of the blades, the flow type is controlled by these parameters. The majority of previous studies employed turbulence models that are only appropriate for fully turbulent flows, and consequently, they mostly caused high discrepancy between numerical predictions and corresponding experimental measurements specifically at geometrical parameters generating laminar and transient flows. The present article proposes a complete procedure of computational fluid dynamics simulation for wetted flows over marine propellers using ANSYS FLUENT 16 and employing both transition-sensitive and fully turbulent models for comparison. The K-Kl-ω transition model and the fully turbulent standard K-ε model are suggested for this purpose. The investigation is carried out for two different propellers in geometrical features: the INSEAN E779a model and the Potsdam Propeller Test Case (PPTC) model. The results demonstrate the effectiveness of the K-Kl-ω transition model for the INSEAN E779a propeller rather than the PPTC propeller. This can be interpreted as the narrow-bladed and small-diameter propellers have more likely laminar and transient flows over its blades.

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