Abstract
Air leakage from a thin radial gap between the flange of a circular pipe and a flat disk is experimentally studied. The effects of the wettabilities of the flange and the disk on the flow coefficient are examined in detail. The height of the gap ranges from about 50 μm to 500 μm. The surface roughness of the gap is varied by coating two types of repellents. The flow coefficient relating the flow rate to the pressure drop of air passing through the gap is experimentally determined and compared with both an analytically obtained equation and an empirical equation proposed so far. As the prediction of the present data by the previously proposed equations is not satisfactory, an empirical equation is newly proposed.
