Abstract: Underwater submerged supersonic gas jet is a gas jet from the orifice or nozzle into water at supersonic speed, which diffuses in water flow and causes complex gas-water mixing and interface instabilities. Firstly, the flow field of the 3-dimensional submerged supersonic gas jet was recorded by a high speed camera in the experiment. Secondly, Ax-symmetric model was established for the experimental case by the VOF method. The numerical and experimental results showed early evolution of bubble motion of the jet and evolution process of a bubble, including generating, growing, being broken by the next one, bulging and back-attack etc. The jet flow field structures, such as distribution of pressure and velocity, Mach number in the flow field during injection were analyzed by numerical simulation. Complex shock wave/expansion wave cell structures existed in the field of the submerged jets, influencing the parameters in the flow fields and leading to the phenomena, such as bulging, back-attack. The results of numerical simulation agreed well with the results of experiment.

Key words: gas-liquid flow, numerical simulation, mixing, submerged supersonic jet, bubble motion

摘要： 从实验和数值计算两方面研究了超声速气体射流在水中的喷射过程.用高速摄影机拍摄了三维水下超声速气体射流的流场.针对实验工况,基于VOF方法,建立水下超声速气体射流的二维轴对称数值计算模型,并开展了相关数值模拟.成功模拟了射流初期气泡运动演化的复杂过程;分析了水下超声速气体欠膨胀射流的流场结构,包括流场的压力和速度等参数分布以及变化规律.数值结果与实验结果对比得知数值计算结果不仅与实验数据吻合较好,而且给出了实验中没有发现的激波、膨胀波等流场结构.

关键词: 气液两相流, 数值模拟, 混合, 超声速浸没射流, 气泡运动