Asymmetrical Propagation of Powerful Sound in Double-Layer Liquid

The asymmetry sound propagation has been observed experimentally in coupling double-layer of liquids with different cavitation thresholds. When the sound wave propagates from the high threshold liquid to the low one, it is possible that both two liquids can avoid the cavitation under suitable driving pressure. However, the driving pressure will cavitate the low-threshold liquid though the high-threshold liquid keeps uncavitated when the sound propagates oppositely. The additional attenuation due to cavitation makes the distribution of the sound field different between two opposite propagations, leading to the asymmetrical sound propagation. The observations can be reproduced by the numerical simulation in framework of the modified two-phase fluid theory.