Large eddy simulation of cavitation vortex interaction and pressure fluctuation around hydrofoil ALE 15

Numerical investigation on cavitating flow around a three dimensional hydrofoil ALE 15 is conducted by means of large eddy simulation. The calculated values of statistical average velocities agree well with the experimental data. Evolution of cavitation shows that the vortex structure and re-entrant jet in the vicinity of hydrofoil surface result in cavitation separation and shedding. The vorticity transport equation with vortex stretching term, vortex dilatation term, and baroclinic torque term is introduced to reveal the mechanism of cavitation-vortex interaction. Analysis results show that the cavitation-vortex interaction is mainly affected by the vortex stretching term and vortex dilatation term. The calculated pressure fluctuations on the hydrofoil shortest side show a pulse shift due to cavitation oscillation. The primary frequency of shedding cavitation is 307.14 Hz, which agrees well with the experimental data of 302 Hz.