ABSTRACT
Forced-convection boiling heat transfer experiments with Freon-113 were performed on thin gold-film heaters under earth gravity and microgravity. The microgravity environment, which was used to unmask the buoyancy effect, was achieved in a 0.6-second airbag decelerated drop tower at Washington State University. The main objective was to experimentally investigate the latent heat transport mechanism and the “sliding bubble” model proposed by Tsung-Chang and Bankoff (1990) for subcooled forced-convection nucleate boiling. In general, during microgravity the heat transfer is enhanced the greatest if individual spherical bubbles rather than vapor chunks are maintained by the forced flow. For this case, we found individual spherical bubbles which slid on the heater surface at 25 to 90% of the free-stream velocity. Forced-convection subcooled nucleate boiling was found to have minimum reliance on gravity and therefore is a feasible and efficient heat transfer mechanism for microgravity applications.
