Visualizing The Flow Induced By An Air Curtain Over A Mannequin Using Stereo Particle Image Velocimetry

Air curtains find widespread applications in today's world, such as in malls, supermarkets, airports, cold storage, etc., to allow easy pedestrian movement between two different environments. There is interest in understanding the flow induced by traffic through the air curtain in terms of energy efficiency and the ability to provide isolation from contaminants and airborne pathogens. To develop an understanding of the flow, an initial exploratory study was performed using a static mannequin. A stereo particle image velocimetry (SPIV) system was set up to map the flow of the air curtain, installed on top of the doorway, over a mannequin. The mannequin, dressed in a black, long sleeved shirt and matching track pants, was placed in the center of the doorway and directly under the air curtain. Two sets of maps were obtained, one parallel to the plane of the jet and the other perpendicular to it. In the first case, three parallel, vertical planes were mapped, starting within the plane of the jet and the others away from it and towards the cameras. In the second case, one vertical plane, which was incident to and at the center of the doorway, without the mannequin was mapped. In either case, each plane was divided into smaller regions which were recorded one at a time. Stereo pairs of 400 images were obtained for each region and then ensemble averaged. The arrays were then stitched together to provide the final, seamless dataset.The velocity maps indicated a low velocity region around the mannequin as compared to the adjoining areas as well as a clear obstruction to the output flow from the air curtain. A high turbulence region was located close to where the air curtain jet and the mannequin first meet. The incident plane, which was recorded to give a general prediction of the flow from the air curtain, indicated a certain unsteadiness of the output flow. This, however, was caused by a clear lack of recorded data. Overall, the results indicate the successful implementation of the PIV system in visualizing the flow from an air curtain over a mannequin.