Experimental and Numerical Simulation of Cavitating Flow Around a Disc

The unsteady cavitating flows around a disc are studied by experimental and numerical methods,where the Reynolds number remains the same and different cavitation numbers are obtained by changing the pressure values.Experiments are carried out in a rectangular test section of a cavitation tunnel;and a high-speed video camera is used to visualize the unsteady cavitation flow patterns.The calculations are conducted for a three-dimensional disc,based on a single-fluid model of the cavitation:the liquid/vapor mixture is considered as a homogeneous fluid with its composition being regulated by the mass transfer equation.A density modified corrected unsteady cavitation closure is used in calculations.The results show that the cavitation around the disc can be well simulated with the density modification based closure,the trend of cavity shapes against the cavitation number and the time is properly reflected.The flow field of the cavitating flows experiences several stages,including the small-scale bubble pulse,the instable bulk cavitation and the stable supercavitation.Here,the unsteadiness of the mass transfer process between the vapor and the two-phase regions is dominant.