Pressure control of large cryogenic tanks in microgravity Original Research Article

This work studies the pressure control of a large cryogen storage tank in microgravity using a series of parametric numerical simulations. The complete governing equations in the liquid region are coupled to a lumped thermodynamic treatment of the vapor region. It is shown that even in microgravity buoyancy effects rapidly bring the vapor region up to the tank wall. Long-term pressurization studies show that natural convection still leads to considerable thermal stratification in the liquid. A subcooled liquid jet is used to control the pressure rise. At its lowest speed, the jet cannot penetrate far enough into the liquid region to cool the vapor because of retarding buoyancy forces. As the jet speed is increased, it is shown to be quite effective at disrupting the thermal stratification and reducing the tank pressure in a reasonable amount of time.