Predicting Flashing Phenomena: A Combined Approach of Numerical Simulation and Experiments

Abstract

The German Aerospace Center (DLR) in Lampoldshausen is investigating new methods for injection and ignition of new green propellants at near vacuum conditions. In this case the focus is on energetic ionic liquids (EIL) based on ammonium dinitramide (ADN). These are thought to be promising substitutes for hydrazine. During the experimental campaign with di�erent transparent injectors (L/D, contraction ratio, nozzle length), nucleation en- hancing internal low regimes like cavitation and even hydraulic ip were detected. The latter two most likely lead to segregation of the propellants and crystallization of the solved ADN-salt. To predict and avoid these phenomena, test cases were repeated with ANSYS® CFX 15.0 and compared to the experimental data.