Physical and numerical study on unsteady shedding behaviors of ventilated partial cavitating flow around an axisymmetric body

摘要

The objective is to investigate the unsteady ventilated partial cavitating flow characteristics with focus on the unsteady shedding behaviors via combined experimental and numerical methods. Experimental results are presented for an axisymmetric body in a water tunnel with the flow pattern recorded by a high speed camera. The numerical simulation is performed with a filter-based turbulence model. Good agreement can be obtained between the experimental and numerical results. The ventilated cavity around the axisymmetric body experiences the rapid growth stage, the growth with small pulsation stage and the periodic shedding stage. The typical ventilated cavitating flow patterns at different angles of attack have also been studied to further investigate the effect of the asymmetry on the unsteady shedding behaviors of ventilated partial cavitating flow. With the increase of the angle of attack, the ventilated cavity develops asymmetrically and the non-transparent gas-liquid mixture region is gradually concentrated on the opposing stream surface along with the transparent cavity region increasing on the confronted stream surface.