Influence of external perturbations on a minienvironment: experimental investigations

摘要

An assessment is made on the influence of external perturbations on an original minienvironment intended for food manufacturing. The minienvironment is a working unit where local displacement ventilation for clean room condition is applied. It consists of a unidirectional flow and an air curtain. Using the particle image velocimetry technique velocity measurements are initially carried out in order to describe the steady flow. Laser tomography and tracer gas experiments are then applied in order to explain the influence of sharp changes of pressure on the flow field and quantify the efficiency of the system. The corresponding results clearly indicate that the minienvironment and particularly the air curtain are strongly sensitive to perturbations. They highlight that perturbations, such as draughts or wind effects, must be taken into account in order to properly design 'open' minienvironments.