Three-dimensional and experimental investigation on the effect of cone length of throttle valve on thermal performance of a vortex tube using k–ɛ turbulence model

Rafiee, Seyed Ehsan; Mohammadkhani, Farzad

doi:10.1016/j.applthermaleng.2014.01.073

Cited by 67 publications

(20 citation statements)

References 29 publications

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“…The RNG k-ε turbulence model and more advanced turbulence models such as the Reynolds stress equations were also investigated, but these models could not be converged for this simulation (Rafiee et al [3]). Rafiee et al [6] showed, for this reason that the numerical results has good agreement with the experimental data, the k-ε model can be selected to simulate the effect of turbulence inside the computational domain. Consequently, the governing equations are arranged by the conservation of mass, momentum and energy equations, which are given by:…”

Section: Governing Equationsmentioning

confidence: 99%

“…Rafiee and Sadeghiazad [4] introduced 3D CFD exergy analysis and Stephan et al [5] proposed the constitution of Gortler vortices on the inside wall of the vortex tube that drive the fluid motion. Rafiee and Sadeghi [6] performed an experimental and numerical work on cone length of control valve of vortex tube. Skye et al [7] employed a model similar to that of Aljuwayhel.…”

Section: Introductionmentioning

confidence: 99%

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3d Numerical Analysis on the Effect of Rounding Off Edge Radius on Thermal Separation Inside a Vortex Tube

Rafiee¹,

Mohammadkhani²

2015

IJHT

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Vortex-chamber is a main part of vortex tube which the pressured gas is injected into this part tangentially. An appropriate design of vortex-chamber geometry leads to better efficiency and good vortex tube performance. In this study, the computational fluid dynamics (CFD) model is created on basis of an experimental model and is a three-dimensional (3D) steady compressible model that utilizes the k-ε turbulent model. In this paper the effect of changing radius of rounding off edge at hot tube entrance (r1) on vortex tube performance has been studied for different value of r1 and the optimized radius has been determined. According to numerical results the cold temperature difference has increased when we take into account the effect of the radius of rounding off edge in the range of 0-1.5 mm and when the radius of rounding off edge has located in the range of 1.5-4 mm, the cold temperature difference has decreased. The highest ΔTc is 47.26 K for r1=1.5 mm at a cold mass fraction of 0.3, higher than basic model around 7.5% at the same cold flow fraction. Finally, the results obtained, particularly the temperature values, are compared with some available experimental data, which s how good agreement.

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Section: Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

3d Numerical Analysis on the Effect of Rounding Off Edge Radius on Thermal Separation Inside a Vortex Tube

Rafiee¹,

Mohammadkhani²

2015

IJHT

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“…The effect of the convergent nozzle intake number on the vortex tubes performance has not been reported yet. On basis of the conclusions for straight nozzles, some reported that increasing the number of nozzles can produce a strong swirling flow field inside the vortex tube and consequently help to improve the temperature separation procedure whereas, some researchers [15] said that the vortex tubes performance decreases with the increase of the nozzles number due to the development of the turbulent flow filed. To indicate the effect of the intake number on the cryogenic capacity of vortex tubes with convergent nozzles, N =2, 3, 4 and 6 nozzles are investigated at inlet pressure of 0.25 MPa with constant parameters K=1.9 and L =250 mm.…”

Section: Resultsmentioning

confidence: 99%

Experimental and numerical study on the effect of the convergence angle, injection pressure and injection number on thermal performance of straight vortex tube

Mohammadkhani¹

2017

IJHT

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Energy separation procedure of vortex tube can be improved by using convergent nozzle. In the experimental investigation, the parameters are focused on the convergence ratio of nozzle, inlet pressure and number of nozzle intakes. The effect of the convergence ratio of nozzle is investigated in the range of 1-2.85. A computational fluid dynamics model was developed to predict the performances of the vortex tube system. The numerical investigation was carried out by full 3D steady state CFD-simulation using FLUENT 6.3.26. This model utilizes the k-ε turbulence model to solve the flow equations. Experiments were also conducted to validate results obtained for the simulation. First purpose of numerical study in this case was validation with experimental data to confirm these results and the second was the optimization of experimental model to achieve the highest performance.

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“…Rafiee and Sadeghiazad [18] analyzed the effect of different boundary conditions (pressure outlet and pressure far field) at the outlets and different working gases on the energy separation inside a vortex tube. Rafiee and Sadeghiazad [19,20] managed some experimental setups to optimize the control valve structural parameters such as the conical angle and the cone length and proved that there are some optimized values which lead to the best thermal capability. The impact of a new shape of the hot tube (the convergent main tube) is experimentally tested by Rafiee et al [21] and Rafiee and Sadeghiazad [22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Experimental study on thermal performance of double circuit vortex tube (DCVT) - Effect of heat transfer controller angle

Mohammadkhani¹

2017

IJHT

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The patterns of heat and mass transfer can be changed using various heat transfer controller angle in Double Circuit vortex tube (DCVT). In this parametric/experimental test, the effective parameter is focused on the heat transfer controller angle in DCVT. The heat transfer controller angle is considered over the range of 20 to 80 degree. The experimental tests indicate that the heat transfer angle should be small and not more than 75 under our experimental tests so there is an optimal heat transfer angle of controller to achieve the highest cooling efficiency. The preliminary experimental results indicate that θ=75 yields the highest cold temperature reduction, which exceeds θ=20 one by about 51.23%. In fact, the optimum model before the optimization was θ=70. Also, The ratio of actual cold temperature difference to the maximum temperature difference, ΔTc / (ΔTc)max, for the vortex tube with truncated cone control valve can be presented as a function of the cold mass ratio.

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Three-dimensional and experimental investigation on the effect of cone length of throttle valve on thermal performance of a vortex tube using k–ɛ turbulence model

Cited by 67 publications

References 29 publications

3d Numerical Analysis on the Effect of Rounding Off Edge Radius on Thermal Separation Inside a Vortex Tube

3d Numerical Analysis on the Effect of Rounding Off Edge Radius on Thermal Separation Inside a Vortex Tube

Experimental and numerical study on the effect of the convergence angle, injection pressure and injection number on thermal performance of straight vortex tube

Experimental study on thermal performance of double circuit vortex tube (DCVT) - Effect of heat transfer controller angle

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