Growth behavior of bubbles containing non-condensable gas in superheated cryogenic liquids

Abstract

Bubble growth is one of the most critical concerns in flashing or cavitation in metastable superheated liquids. The bubble growth rate and heat and mass transfer rates across the boundary are essential for quantifying the flashing evaporation behavior. Prior simulations treated the bubble as a pure vapor, which dropped an important influencing factor driving bubble growth. A mathematical model is proposed for characterizing bubble growth in superheated cryogenic liquids, namely, liquid oxygen, hydrogen, and nitrogen. The model considers a non-condensable gas component in the bubble, which plays a significant role in the early stages of bubble growth. It not only influences the critical radius of the bubble but also affects the delay time of the growth. The behavior of bubbles in these cryogenic fluids was compared to that in water in terms of radius growth. The effect of the liquid state on the bubble radius was investigated. As expected, the bubble grew faster in the liquid at lower pressures and greater degrees of superheat. Bubbles with smaller critical radii require higher degrees of superheat or thermal disturbances to grow.