Temperature measurements in a multiphase fluid hammer

Abstract

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.

Any satellite propulsion system is inactive at launching, having the liquid propellant confined into tanks and the propellant lines vacuum pumped or filled with a noncondensable gas (NCG) at low pressure. Once in orbit, the propulsion system performs the so-called priming maneuver that consists in filling these lines with the pressurized liquid propellant (hydrazine), by opening a fast isolation valve. The opening of this valve subsequently induces a fluid hammer, together with various multiphase phenomena, such as cavitation and gas desorption. On top of that, the adiabatic compression that the liquid propellant may experience can induce the explosive decomposition of hydrazine. Nowadays, the propulsion systems are certify with CFD simulations, but the numerical models still need to be extended and validated to work with multiphase fluids. The aim of this paper is to study experimentally the pressure and temperature evolution in the propellant lines during water hammer occurrence. The creation of an experimental database is a requirement to validate the numerical tools modeling the propulsion systems.