Experimental investigation of ventilated partial cavitating flows with special emphasis on flow pattern regime and unsteady shedding behavior around an axisymmetric body at different angles of attack

The objective of this paper is mainly to investigate the ventilated partial cavitating flow structure at different angles of attack with experimental methods. A high-speed camera technique is used to record cavity evolution patterns. The numerical simulation is performed by CFX Solver with a free surface model and filter-based turbulence model. Three flow pattern maps are constructed to depict the flow pattern and structures at different angles of attack alpha, i.e. the range of Froude number Fr and gas entrainment coefficient C-Q. The maps show that the angle of attack alpha has a significant effect on ventilated cavitating flow structures. With the increasing value of alpha, the asymmetry of ventilated cavity becomes obvious and the angle between the axis of the body and the closure line theta is decreased. The value of the included angle theta is found to vary with Fr number and C-Q. The cavity break-off may be mainly determined by the momentum and the direction of re-entrant jet flow.