Numerical investigation of scale effect of various injection diameters on interaction in cold kerosene-fueled supersonic flow

The incident shock wave generally has a strong effect on the transversal injection field in cold kerosene-fueled supersonic flow, possibly due to its affecting the interaction between incoming flow and fuel through various operation conditions. This study is to address scale effect of various injection diameters on the interaction between incident shock wave and transversal cavity injection in a cold kerosene-fueled scramjet combustor. The injection diameters are separately specified as from 0.5 to 1.5 mm in 0.5 mm increments when other performance parameters, including the injection angle, velocity and pressure drop are all constant. A combined three dimensional Couple Level Set & Volume of Fluids (CLSVOF) approach with an improved K-H & R-T model is used to characterize penetration height, span expansion area, angle of shock wave and sauter mean diameter (SMD) distribution of the kerosene droplets with/without considering evaporation. Our results show that the injection orifice surely has a great scale effect on the transversal injection field in cold kerosene-fueled supersonic flows. Our findings show that the penetration depth, span angle and span expansion area of the transverse cavity jet are increased with the injection diameter, and that the kerosene droplets are more prone to breakup and atomization at the outlet of the combustor for the orifice diameter of 1.5 mm. The calculation predictions are compared against the reported experimental measurements and literatures with good qualitative agreement. The simulation results obtained in this study can provide the evidences for better understanding the underlying mechanism of kerosene atomization in cold supersonic flow and scramjet design improvement.