Numerical simulation for variations of airflow induced by an object getting in and out of a workbench

Abstract

The variations of airflow patterns induced by an object getting in and out of a workbench in a vertical laminar flow cleanroom are studied numerically. This subject is an important issue of microcontamination control for fabrication of precision devices. The characteristic of the variations of the airflow is dynamic and is a type of moving boundary problem. An arbitrary Lagrangian-Eulerian (ALE) kinematic description method is employed to describe the flow field, and a penalty finite element formulation with moving meshes is adopted to solve this problem, Three different moping speeds of the moving object with Reynolds number Re =500 are considered. The results show that the formation of recirculation zones, which inhibit removing contaminants, is remarkably dependent upon the moving speed of the object getting in and out of the workbench.