双股等离子体射流在液体工质中的扩展特性研究OA

In order to investigate the expansion characteristics of twin plasma jets in liquid under the background of electrothermal chemical emission,a three-dimensional unsteady model of the interaction between plasma jets and liquid was developed,and numerical simulations were conducted to analyze the expansion characteristics of twin plasma jets in liquid.The distributions of the two-phase and the streamlines in the flow field,distributions of pressure,temperature,and velocity were acquired.Results show that twin plasma jets firstly expand in the radial direction at the bottom in the chamber,and then expand rapidly in the axial direction.Due to the Taylor-Helmholtz instability,the head of the jet is pointedly conical,and the profile is broken and folded.The inner profile fluctuation is more intense than the outer one due to the mutual interference of the jets between the two phases.The necking phenomenon occurs at the outer side of the jet near the nozzle due to the squeeze of the return flow of the liquid.The velocity of the inner side is higher than that of the outer,therefore,the high-speed area of the velocity field shows a tendency to converge to the center.The pressure and temperature are affected by the alternation of expansion wave and compression wave,and there is a structure of high and low values fluctuation.In the late stage of twin plasma jets expansion,large vortexes are formed in the middle outer side of the flow field which will obviously consume the energy of the plasma jets,and the pressure and temperature decrease significantly.