A numerical investigation of effects of a moving operator on airflow patterns in a cleanroom

Abstract

The variations of the airflow induced by a moving operator in a cleanroom installed with a curtain were studied numerically. This situation is cataloged to a class of the moving boundary problems. An arbitrary Lagrangian-Eulerian kinematic description method is utilized to describe the flow field and a penalty finite element formulation with moving meshes is adopted to solve this problem. The effects of the moving operator and curtain on the airflow patterns under different distances from the workbench to the curtain with the moving speed of the operator equal to 2.0 and Reynolds number Re = 500 are taken into account. The results show that recirculation zones are formed around the operator and workbench due to the movement of the operator. The recirculation zones are not favorable to the cleanroom because they may induce a local turbulent flow and entrain and trap contaminants. These phenomena are remarkably different from those of the moving operator assumed as stationary in the cleanroom. Based on the length of the curtain, it is useful for protecting the operator from the hazardous gases. (C) 2002 Elsevier Science Ltd. All rights reserved.