College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, P.R. China
Artificial supercavitation is one of the most prospective technique for underwater drag reduction, but it still faces some unsolved roadblocks, like cavity stability, noise, power etc. This article aims at investigating the instability of cavity with the strong jet impingement, and analyzing jet behavior in restricted space. A multiphase model using coupled VOF and level set method is adopted to capture the gas-liquid interface. By changing the position of jet nozzle exit and the jet intensity, a series of numerical simulation is performed. Firstly the transient evolution of the cavity interface under the effect of the high-speed jet is obtained. Numerical model is validated by comparing with the experimental data. Then the criterion to determine the transition between different jet/cavity interaction mechanisms is established based on a non-dimensional distance parameter. Furthermore, the entrainment mechanism inside the cavity is analyzed and provides useful insights on enhancing the cavity stability with strong jets.