Fluid hammer with gas desorption in a liquid-filling tube: experiments with three different liquids

Abstract

The opening of a fast valve followed by a fluid line with a closed end generates a fluid hammer that may involve several multiphase phenomena. This is the case of the propulsion systems in satellites during the priming operation, where the lines are initially kept under vacuum conditions. The filling with liquid propellant is done by opening a pyrotechnic valve, and the fluid hammer taking place involves cavitation and gas desorption. For this purpose, an experimental study is carried out with inert fluids modeling a liquid propulsion system, where the saturation level of the test liquid is controlled, allowing to run experiments under deaerated and saturated conditions. The results show that the fluid hammer phenomenon is affected by the gas saturation conditions if the liquid is susceptible to high desorption rate. In this case, the desorbed pressurant gas in the lines cushions the liquid front impact at the closed ends, leading to a lower pressure rise during fluid hammer occurrence.