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.