Preliminary Validation and Sensitivity Analysis on a Eulerian/Lagrangian RANS Approach for Liquid Injection in Supersonic Crossflow

Physical phenomena related to liquid jets in supersonic crossflows are fundamental for several applications in the aerospace propulsion field. A preliminary validation of a Eulerian- Lagrangian RANS-CFD is conducted on a testcase employing water injection in a M=1.94 crossflow with a jet-to-freestream momentum flux ratio q=7. After presenting the numerical models, the effect of turbulence is investigated by performing simulations using the RNG k-ε, Menter SST k-ω, and Reynolds Stress Model (RSM), retaining the breakup sub-model constants at their default values. A sensitivity analysis is then conducted by varying some parameters of the latter, highlighting a greater influence of the parameter associated with the critical breakup radius in the Kelvin-Helmholtz model. The results show that the differences between the various turbulence closure models are minimal in this configuration. The consistency of the results with the physics of the problem is critically reviewed, revealing some discrepancies compared to experimental data in terms of liquid presence on the wall and trends in the Sauter mean diameter and velocity along the penetration direction coordinate. A calibration procedure for the k-ω model is proposed, based on fitting the obtained data and the maximum expected SMD. The calibrated simulation shows improved results in terms of agreement with penetration height, SMD and particle velocity.