Boiling heat transfer enhancement by using micro-structure surface under microgravity

For the purpose of cooling electronic devices in space systems with high heat flux efficiently, experiments of highly subcooled pool boiling of FC-72 on micro-pin-finned surface structure were studied in short-term microgravity utilizing Drop-Tower Beijing with duration of about 3.6 s. The micro-pin-fins were fabricated on the silicon chip surface with the dry etching technique. The silicon chip was heated by means of controlling heating dc current for the desired heat flux. The bubble behavior for a smooth surface was also provided for comparison. The results indicated that the performance of high efficient heat transfer on micro-pin-finned surface is independent of the gravity, which stems from the sufficient supply of fresh liquid to the heater surface due to the capillary forces.