Using the molecular dynamics method of LAMMPS software in OpenFOAM open source software to analyze a gas centrifuge machine

Abstract

In order to modeling the gas behavior inside the rotor of a gas centrifuge, a powerful tool is needed to overcome the computational constraints of gas inside the centrifuge along with the ability to apply all drives at the all flow regimes. Due to the suitability of the DSMC method for all flow regimes formed inside the centrifuge, in this paper, the DSMC method is used to analyze the separation performance of a centrifuge in axisymmetric coordinates. For this purpose, using a multi-scale CFD-MD method, first the momentum accommodation coefficients required to use the Cercignani-Lampis-Lord boundary condition are extracted and then, based on that, the behavior of the gas inside a centrifuge machine is investigated using the DSMC method and the amount of separation power is determined. Based on the comparison of the simulation results with the experimental test results, it was shown that using the proposed hybrid method to determine the amount of momentum accommodation coefficients used in the CLL boundary condition of the DSMC method, can increase the accuracy of determining the amount of separation power of the machine up to 8%.

Keywords

• gas centrifuge
• openfoam
• dsmc code
• multi-scale method
• molecular dynamics