Numerical research of compressible turbulent swirl flow with energy separation in a cylindrical tube

Abstract

The aim of this paper is to numerically analyze the energy separation phenomenon in turbulent compressible swirling flow in a cylindrical tube. In that sense, the energy separation in a vortex tube with orifice at cold end closed completely is examined numerically using OpenFOAM software. Obtained results are validated with the experimental ones. For numerical calculations, both two-equation (standard k-ε) and full Reynolds stress turbulence models (LRR) are used. The computational domain is considered to be two-dimensional, and the working fluid-air is treated as calorically perfect gas. Mesh independence test is carried out for four different mesh sizes. Distributions of swirling flow intensity, average swirl and angular velocity clearly show the influence of the swirl presence in the flow. The values of these quantities point to the physics of this extremely complex flow-thermodynamic phenomenon, such is the energy separation. Based on values and distributions of these flow quantities a comparison between incompressible and compressible turbulent swirling flow is performed.

Numerical Study of the L/D Ratio and Turbulent Prandtl Number Effect on Energy Separation in a Counter-Flow Vortex Tube

“…These solvers can calculate compressible turbulent flow, and are obtained by modifying existing solvers within OpenFOAM software, which is described in more detail in . Eckert-Wiese phenomena is already investigated by the OpenFOAM software in flow across cylinder in , June, 2018, and research on vortex tube's energy separation using modified solvers is presented in and Burazer et al 2019).…”

“…We have set the boundary conditions as described in Burazer et al (2019); inlet: fixed temperature and velocity, pressure gradient equal to zero, turbulence intensity 5%; outlet: fixed pressure, inletOutlet boundary conditions for velocity, temperature and turbulence quantities; walls: a no slip boundary condition for velocity and gradient equal to zero of all other quantities. InletOutlet boundary condition allows the possibility of reverse flow on this boundary.…”