The computational fluid dynamics (CFD) technique is used to investigate the thermal-dynamic coupled process in cryogenic liquid oxygen tank under the slosh excitations. The influences of the external environmental heat leak and the phase change occurring on the liquid-vapor interface are considered in detail. The slosh force

fluid slosh momentum

tank pressure

and fluid temperature distribution in tank caused by the external excitation are analyzed. The results show that both the slosh force suffered by tank and fluid slosh momentum have reducing trends with fluctuations under the external sinusoidal excitation. Influenced by the external slosh

the connection area between the subcooled liquid and the superheated vapor increases

so the superheated vapor is greatly cooled by the liquid

and the tank pressure decreases almost linearly with time. As for the fluid temperature monitors

while they are close to the liquid-vapor interface

the fluid sloshing has an obvious effect on the variation of monitors' temperature. In general

the temperature distribution in the tank is formed with the high temperature region in upper and low temperature region in bottom

and the high temperature in the external region and the low temperature in the interior. While as located on the top of tank

the vapor test points have a large temperature fluctuation

influenced by the top dished-head. For the bottom liquid temperature monitors

their values are larger than parts of liquid test points' temperature

with the direct heat transfer from the bottom dished-head wall.