A critical aspect of high-speed air-breathing propulsion systems is liquid fuel injection into supersonic flow.The lack of understanding of primary and secondary breakup of liquid columns into droplets, spray plume interaction with shocks and droplet evaporation in high enthalpy flows can only be partially mitigated by targeted experiments.To fill in essential insight, the development of numerical models, when coordinated carefully with experimental efforts, offers significant potential to enable predictive capabilities to enhance the development of high-speed propulsion systems.This effort shall investigate hybrid two-phase liquid injection models that account for full momentum coupling between the phases near the injector and that transition to a dispersed phase model after primary breakup of the liquid column into droplets.The boundary of the pure liquid jet will be tracked to allow liquid stripping and breakup models to be evaluated.Secondary droplet breakup and evaporation models can then be tested in the Lagrangian framework.Evaluation of the modeling assumptions and definition of validation procedures will be coordinated with available experimental data for plume structures, droplet size distributions and droplet velocity profiles.The predictive capability will enhance analysis of liquid injection into high enthalpy flows that are representative of a scramjet environment.liquid injection,interface capturing,primary breakup,two-phase flow,air-breathing propulsion,Scramjet
