Investigation on Pressure Change Induced by Cryogenic Sloshing

Abstract

Pressure drops in the non-isothermal sloshing of liquid nitrogen and liquid hydrogen were experimentally investigated. Heat and mass transfer indicated by the pressure change induced by violent sloshing in the cryostat driven by the mechanical exciter were successfully obtained. Based on the visualized image of liquid motion, it was found that splash and wavy surface induced by violent sloshing of liquid should enhance heat transfer around liquid surface and result in pressure drop. It was also suggested that the instability of singlecomponent system with different temperature between the gaseous and liquid phase could make the pressure control more difficult. Nomenclature  : density [ kg/m 3 ] p : static pressure [ Pa ] T : static temperature [ K ] e : internal energy [ J/kg ] u  : velocity [ m/s ] g  : gravity acceleration [ m/s 2 ] q  : heat flux [ W/m 2 ] C p , C v : specific heat at constant p or  [ J/(kg･K) ]  : viscosity coefficient [ Pa･s ] k : thermal conductivity [W/(m 2 ･K) ]  : surface tension [ N/m ] D : diameter of vessel [ m ] t : time [ sec ]

Experimental Investigation on Heat Exchange and Pressure Drop Enhanced by Vertical Sloshing

“…As shown in Fig.5, compared with the visualized motion of liquid, the enhancement of hear transfer coupled with the non-linier motion, such as the appearance of droplets and wavy surface, had different order of magnitude from those in the cases with linier response. In AIAA 2012-4295 10) , non-isothermal sloshing of liquid nitrogen and liquid hydrogen accompanied by phase change were successfully visualized. As shown in Fig.6, pressure drop was found to depend on the composition of gaseous species.…”