Numerical study of particulate turbulent flow to investigate recovery period in cleanrooms

The Clean room is a controlled space and is used in various industries such as electronics, medical and military industries. One of the most important tests to evaluate the performance of the cleanroom is recovery test. Recovery test determines the time period during which a clean room returns to its designated cleanliness level after an instant or a period of deliberate or unintentional contamination. In this paper, a thorough investigation of recovery period has been implemented. In this study, air change rate and its pattern were studied using the Eulerian and Lagrangian approaches and LES, DES and k-ω SST turbulent models. Simulation results were evaluated against control volume analysis. Parameters such as the air change rate, the number of particles, and pressure and energy consumption in various radial and tangential angles of diffusers were studied Results showed that radial angle had little positive and occasionally negative effect on recovery period. On the contrary, tangential angle improved decontamination rate, at maximum performance (β=45°), it could reduce recovery period as much as 25% which in turn reduces energy consumption. In addition the DES model provides the best and most coinciding answers between all turbulence models.