Numerical simulations of nano-particle's drag forces using DSMC method for various Knudsen numbers

Abstract

In this study, high-vacuum flow was analyzed using the direct simulation Monte Carlo (DSMC) method, and various forces acting on fine particles in a high-vacuum flow field were studied. The DSMC method is a Lagrangian method that models the flow as particles and analyzes the collisions and behaviors of each particle, which costs a large computing resource. To validate DSMC method, computational results of a Poiseuille flow in microchannel are compared with analytical results. In addition, the force acting on the particles in the high-vacuum rarefied gas region was verified using the outputs of previous studies. Through this numerical analysis, it is possible to analyze about regions that are difficult to proceed with experiments. As a result, the drag forces according to the Knudsen number which indicates the ratio of vacuum and the particle size, it was confirmed that the drag force can be predicted through the empirical formula of previous studies.