Numerical analysis of spray characteristics with liquid nitrogen

摘要

Spray of cryogenic fluids, which involves complicated aerodynamic instability and superheat flashing, is receiving increasing attention in cryogenic cooling applications and cryogenic propellant ignition. In the present study, a two-fluid numerical model coupling the Algebraic Interfacial Area Density (AIAD) model and Homogeneous Relaxation Model (HRM) framework was built to investigate the underlying physics of liquid nitrogen (LN2) spray. The proposed approach aims at describing the underlying physics affected by both aerodynamic and flashing dynamics. Behaviors of spray characteristics, including flow regime, pressure distribution, velocity distribution and intact core length, are analyzed subsequently. Accordingly, effects of aerodynamic instability and flashing on the LN2 spray were analyzed. Finally, a modified correlation of liquid-intact-core length which involves both of the aerodynamic and thermodynamic effects was proposed and the weight of two effects were evaluated accordingly.