Gravity-Independent Oscillate Boiling

Heat transfer in nucleate boiling relies on the detachment and rise of the boiling bubble, in which gravity plays the dominant role. Previous studies showed that in the absence of gravity, the bubble fails to rise, causing the dryout of the heater and significantly reducing the thermal efficiency of nucleate boiling. Recently, a new boiling regime termed oscillate boiling was discovered. By localizing thermal energy as high as 50 mW into an area as small as 15x15 mu m(2), a boiling bubble is formed and oscillate at high frequency while remaining pinned at the heating spot. This regime was proposed to be independent of buoyancy as its operation does not involves the detachment and rise of the boiling bubble. To test this hypothesis, we compared experimental observations of oscillate boiling in low gravity, normal gravity and hyper gravity. The results support the hypothesis and promote its potential for outer-space heat transfer application.