212 An Experiment on Subcooled Pool Boiling for Microgravity

Abstract

Microgravity experiment on subcooled pool boiling of water was performed by using a thin stainless steel plate for heating surface. No coalesced bubbles were observed to detach from the heating surface under the microgravity. 0n the ground experiment, a flat plate was placed on the heating surface with small clearance to simulate the attached boiling bubbles on the heating surface. Burnout heat flux was measured with respect to the heating duration and an effect of surface roughness on burnout heat flux was investigated under the normal gravity. The burnout heat flux decreased gradually over the microgravity duration and became constant. The rough heating surface was observed to accelerate the bubble growth and give the higher burnout heat flux.