Consideration on possibility of cavitation induced ignition in liquid hydrogen system

Abstract

In this paper, we report the examination situation about the hypothesis that cavitation (bubble collapse) is the ignition source. Cavitation occurs due to sudden change of pressure and temperature of fluid, causes structural damage to the inner surface of the piping and the pump. There were some cases in which this cavitation is presumed to be the cause of hydrogen self-ignition, and experiments are being conducted to clarify the phenomenon. By the previous examination, the hypothesis that hydrogen ignited by the bubble collapse caused by the pressure and temperature change of the fluid was rejected. At present, we are conducting experiments to test hypotheses that bubble collapse caused by impact from droplets is the ignition source.