Experimental study of nucleate pool boiling of FC-72 on micro-pin-firmed surface under microgravity

In order to effectively enhance the boiling heat transfer under microgravity, experiments were performed using micro-pin-finned structure as heater surface in subcooled nucleate pool boiling of FC-72 under short-term microgravity condition utilizing the drop tower Beijing. Micro-pin-fins with the dimensions of 30 x 60 mu m(2) (thickness x height) and the space of 30 pm were fabricated on the surface of square silicon with the dimensions of 10 x 10 x 0.5 mm(3) by using the dry etching technique. The results were compared with previous published data of smooth chip both in normal gravity and microgravity conditions. The micro-pin-finned chip showed a considerable heat transfer enhancement in the nucleate boiling region with higher upper limit heat flux and lower mean heater surface superheat compared to chip S under microgravity condition. The high-efficient heat transfer performance of FC-72 on the micro-pin-finned surface is independent of gravity, which stems from the sufficient supply of fresh liquid to heater surface due to the capillary forces. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.