Investigation of feed flow effect using CFD-DSMC method in a gas centrifuge

Abstract

In this study, the effect of the rarefied region in the centrifuge rotor was investigated. In a centrifuge rotor, the feed inlet is positioned in the rarefied area. The continuum hypothesis is not valid in the rarefied area; therefore, it desires to be analyzed by probabilistic methods like Direct Simulation Monte Carlo (DSMC). The present study uses the Computational Fluid Dynamic (CFD) method to simulate the continuum area, and the DSMC method is employed in the rarefied area. An implicit coupled density-based scheme was performed for the CFD method, and Variable Hard Sphere (VHS) and diffuse models were employed in the DSMC method. Also, the local Knudsen number was defined to determine the interface location between the continuum-rarefied regions (r=0.086 m). The comparison results of pure CFD and CFD-DSMC methods illustrated large differences between the flow properties in the rarefied regions. The results showed that the value of separation power obtained from pure CFD and CFD-DSMC solution is 10.5% different.