Turbulent flow fields of velocity and diffusion in several types of conventional clean rooms are precisely analyzed both by model experiment and by numerical simulation based on the k-ε two-equation turbulence model. The detailed analyses of contaminant diffusion by simulation make it possible to comprehend clearly the structures of velocity and diffusion fields in clean rooms.

The flow fields in such rooms, as analyzed here, are mainly characterized by the inflow jet and the rising streams around it. The combination of one jet and rising streams forms a "flow unit." The total velocity field and the resulting diffusion field of contaminant in a room are well modeled as serial combinations of these "flow units."

Units: SI