Competition between instability mechanisms of a supersonic overexpanded air jet as it flows into water

An analysis is made of the structural features of turbulence formed when a supersonic air jet flows into water. At a qualitative level, a comparison is made of the flow pattern when an air jet flows into air and water. The results of numerical simulation of the jet velocity field are used to analyze the Kelvin–Helmholtz and Rayleigh–Taylor instability mechanisms and to identify the dominant mechanism in various jet propagation regions. The results obtained are compared with experimental high-speed photographic recording data and available numerical calculations.