Author(s): Zhiyong Dong; Yihong Wu; Dong Zhang
Keywords: Air concentration; cavitation cloud; cavitation number; offset; wall pressure
Abstract: An experimental investigation of the cavitation characteristics of high-velocity flow over an offset-into-flow with various heights and chamfers both in the presence and absence of aeration was conducted in a cavitation tunnel of the Hydraulics Laboratory, Zhejiang University of Technology in China. The 2- and 5-mm abrupt and sloping offsets into flows were employed to be models of surface irregularities. Cavitation phenomena of high-velocity flow over the various offsets were carefully observed. A range of air concentrations was considered. Variations of wall pressures downstream and upstream of the offset were measured in terms of the air concentration. The effects of air concentration and chamfer on the cavitation characteristics of the offsets were analysed. In addition, the cavitation cloud over the offset-into-flow and the turbulent boundary layer over a flat plate are compared.