Preliminary control of the air entrainment in bow wave based on the Liutex force method

Trails induced by air entrainment of bow wave breaking can be observed clearly around an advancing ship, making it prong to be detected and causing reduction in hydrodynamic performance. In breaking bow wave region, different scale of coherent vortex structures related closely to the air entrainment are generated. The formation and evolution of bubble clouds can be accounted partly by the swirling vortex flow of the jet plunging. In this work, high-fidelity simulation of the bow wave breaking around a rectangular thin plate is performed with the in-house code BAMR-SJTU. A Liutex force model is constructed to investigate the interaction between the free surface and vortices, and to explore the possibility of alleviating or controlling the air entrainment. This study is the first attempt to manipulate vortices corresponding to the air entrainment of the bow wave breaking. Some typical vortex structures based on the Liutex vortex identification method and the distribution of the vortex force are presented. Comparison of the vortex structures and the entrapped bubbles is conducted to illustrate the efficiency of Liutex force model in air entrainment control.