Mixing Characteristic Of Kerosene Spray In Supersonic Crossflow

The present study,focusing on the liquid jet in supersonic cross flow,investigated the mixing characteristics of liquid jet from plate with or without cavity by Two Phase Large Eddy Simulation(LES)method and Particle Image Velocimetry(PIV)methodology.A Two Phase Large Eddy Simulation method was developed via modeling the movement,evaporation and fragmentation process of sparse liquid droplets based on Lagrange method and the present gas-phase Large Eddy Simulation.Due to the presence of the discrete phase,some special numerical methods such as droplet positioning and optimization and tri-linear interpolation method were proposed.The gas-liquid interaction process of liquid jet into a Ma=1.94 supersonic cross-flow were investigated numerically using this Euler-Lagrange method.Numerical results indicated that there were strong interactions between the airflow and liquid spray.Taylor Analogy Breakup(TAB)model were developed and the simulation results successfully revealed the drawing phenomena of liquid jet breakup which have been discovered by previous experiment.The influence of pressure drop and the diameter of injector on mixing characteristics of keresone jet were investigated by means of PIV and Two Phase Large Eddy Simulation.Results indicate that the increase of pressure drop or diameter of injector both lead to the increase of penetration and lateral extension of kerosene spray and gaseous kerosene.Compared to pressure drop,the diameter of injector is more significant on the flow rate.The increase of diameter of injector leads greater influence on the diffusion of gaseous kerosene.The mixing characteristics of two phase nearby or in cavity with kerosene jet were investigated in supersonic cross flow.Results indicated that the presence of the liquid jet makes the flow pattern inside the cavity change significantly.The concentration of kerosene spray and gaseous kerosene in the cavity are affected significantly by the pressure drop,the diameter of injector and injection distance.For each factor,the most suitable parameter for the ignition in cavity were given by the analysis of local equivalence ratio and local temperature field in cavity.