CFD optimization of injection nozzles geometric dimensions of RHVT-machines in order to enhance the cooling capability

Abstract

In this article, by using Computational Fluid Dynamic techniques, the optimized dimensions for injection nozzles of vortex tube machine are obtained. For this purpose, numerical simulation for different dimensions of length, width and height of nozzles is performed. However, other dimensions of modeled vortex tube are considered constant. The standard k-ε turbulence model was introduced to the governing equations for analyzing highly turbulence and compressible flows. The main goal of this study is to achieve the minimum amount of cold exit temperature by changing the dimensions of injection nozzles. In addition, an investigation is done upon pressure effect in the vortex tube chamber and its relation with the cold exit temperature and the best dimensions of nozzles are selected. Finally, some results of this article are validated by available experimental data. The comparisons show reasonable agreement.

Comparison of an analytical and computational fluid-dynamics models of a commercial Ranque-Hilsch vortex tube operating with Air and Methane

“…It should also be mentioned that the use of axi-symmetric or two-dimensional models to simplify computational calculations is a trend in the literature consulted; however, the hypothesis that the flow inside the vortex tube is axi-symmetric is not consistent with the actual flow nature, which is why the use of simplifications (in which a section of the tube is modeled) is not considered in this work. Moreover, this numerical study represents an approach, using methane as working fluid, to the vorticity phenomenon in a commercial Ranque-Hilsh vortex tube, with a view to coming up with a tool that provides preliminary information on vortex tube industrial implementation for liquefying natural gas; In addition, we hope that this study contributes to the understanding of the energy separation phenomenon within the device, for further research that includes the integration of vortex tubes in thermal cascades, for example, and other uses, such as those investigated by Bazgir, Adib & other authors [8]- [11].…”

A review on the vortex tube geometrical affecting paramters

“…For rectangular shape straight flow nozzle, the optimum dimensions, including the cross-section width and height are investigated computationally by A. Bazgir and A. Heyderi (2018) [7] (Figure 13 For constant dimensions and inlet flow conditions to the VT, the nozzle height effect is small in spite of the nozzle width that produces more temperature drop for cold flow. The results validation with experimental survey studies showed that the K-Ɛ model achieved the best accuracy results for the cold gas temperature variation with its mass fraction ( Figure 14).…”

“…The adopted VT test rig[6] The cold flow temperature drop with its mass fraction change[6] The cold flow temperature drop with its mass fraction change[6] The definition of the VT nozzle dimensions[7] …”

CFD simulation on optimum material to fabricate the counter flow of Ranque–Hilsch vortex tube

“…Based on these observations, the patterns of large-scale velocities and energy distribution of the vortex tube were determined. Bazgir et al 25 investigated obtaining the minimum cooling outlet temperature by changing the injection nozzle angle. In addition, the effect of pressure on the vortex tube chamber and its relationship to the cold exit temperature and the optimal nozzle passage was selected.…”