Computational Analyses of Cavitating Control Elements in Cryogenic Environments

The safe and reliable operation of high pressure test stands for rocket engine and component testing places an increased emphasis on the performance of control valves and flow metering devices. In this paper, we present high fidelity computational analyses of cavitating venturi-type cryogenic control valves used to support rocket engine and component testing. The computational analyses are carried out with a generalized multi-phase formulation for cavitation in fluids operating in regimes where thermodynamic effects become important. The thermal effects and the accompanying property variations due to phase change are modeled rigorously. Thermal equilibrium is assumed and fluid thermodynamic properties are specified along the saturation line using the NIST-12 databank. The thermodynamic cavitation framework has been validated against experimental data of Hord [1] for hydrofoils operating in liquid nitrogen and liquid hydrogen. In this paper, we will discuss performance losses related to cryogenic control valves and provide insight into the physics of the dominant multi-phase fluid transport phenomena that are responsible for the choking like behavior of cryogenic control elements.