Review of gas jet flow features and its ballistic influences of underwater launch
The underwater launching technology is the key factor to realize the high-speed maneuver of deep-water weapon system.Because of the high density and high back pressure of the fluid environment in the deep ocean,the expansion process of tail gas jet is subjected to the fluid resistance,which results to the complex flow phenomenon with high temperature,high dynamic pressure and gas-liquid multiphase flow.The transient flow characteristics of underwater launch are focused,and the launching process from several aspects is reviewed,including the instability of the supersonic jet,the flow separation of the over-expanded nozzle,the phase change and heat transfer between high temperature gas and water,and the coupling influences of the gas jet and cavitating flow,etc.Moreover,the effects of gas jet flow on the underwater launching trajectory are discussed from the deep-water ignition and thrust stability,etc.Finally,the development trend of underwater launch technology is also demonstrated.Overall,the goal of the above analyses is to provide theoretical references for the engineering applications of underwater launching technology.