Simulations of Injection of Liquid Oxygen/Gaseous Methane Under Flashing Conditions

The startup of in-orbit rocket engines using cryogenic propellants is characterized by near-vacuum conditions leading to rapid flash evaporation of liquid oxidizer or fuel before ignition. The evolution of a flashing oxygen spray as well as the interaction with a coaxial gaseous methane injection is studied and compared to experiments using numerical methods. A flash evaporation model for superheated cryogenic droplets using an Euler-Lagrange method is implemented into a computational fluid dynamics solver. A simplified droplet flash evaporation model is used to calculate the coupling between Eulerian and Lagrangian phases with their respective source terms.