Numerical simulation and modeling of a liquid jet in supersonic crossflow

In this work, a liquid jet in supersonic crossflow (LJSC) was simulated by solving the quasi-conservative five-equation model with surface tension and viscosity terms. The jet trajectory and deformation were detailedly validated against experimental data, showing excellent agreement. Detailed turbulent vortices were identified in the flow field, further confirming the accuracy of the numerical schemes. The influence of Mach number on jet morphologies and trajectories was investigated under constant injection velocity conditions. As the Mach number increases, the liquid jet exhibits reduced penetration and faster fragmentation. The column breakup mechanism shifts from the development of axial instability waves at lower Mach numbers to intense aerodynamic drag at higher ones. By analyzing the relationship between the bow shock wave and jet deflection, a bow shock model was proposed and validated using simulation results. Furthermore, a theoretical model was developed to describe the primary breakup process of LJSC, incorporating the effects of critical forces, jet deformation, mass stripping, and the bow shock wave. The proposed model demonstrated significantly higher accuracy in near-field trajectory prediction compared to existing empirical correlations and proved applicable across a wide range of Mach numbers.