395 / 2022-02-04 17:11:15

3-D numerical investigation into the hydroacoustic effect of cavity depth on low Mach number cavity in water

cavity flow; underwater noise; pulsation pressure; cavity depth; Large eddy simulation

 The characteristics of cavity hydroacoustic influenced by cavity depth were investigated using large eddy simulation together with the acoustic analogy method. The first aim within this study is to explore the prominent frequency band of underwater open-cavity linear spectrum noise for cavities with different depth. Furthermore, through compare the cavity flow period, boundary layer thickness and the circulation law of flow in cavity, the principle that the sound field exhibits different laws has been explored. Shear-layer feedback loop and the inner-flow recirculation together affecting feedback mechanisms oscillation of the cavity, therefore, cavity depth affects the peak frequency and the maximum sound pressure level through change the characteristic of inner-flow recirculation. When D/L ratio less than 1.5, whether there displayed linear spectral noise at the self-sustaining oscillation frequency occurs different characteristics, while the change gradually becomes not obvious as D/L ratio greater than 1.5.