TERRESTRIAL AND MICROGRAVITY POOL BOILING HEAT-TRANSFER FROM A WIRE IN AN ACOUSTIC FIELD

Pool boiling heat transfer experiments from a platinum wire healer in FC-72 liquid were conducted under terrestrial and microgravity conditi ons, both with and without the presence of a high intensity acoustic s tanding wave within the fluid. The purpose of this research was to det ermine the effects of an acoustic sound field on nucleate pool boiling in both terrestrial gravity and microgravity. The platinum wire heate r was used as a constant heat flux source and as a thermometer. The ef fects of acoustics on heat transfer were measured by the change in the average surface temperature of the heater. In terrestrial gravity a p artial boiling curve was established with and without acoustics. In ge neral, it was found that both the natural convection and boiling heat transfer rates were increased with the presence of an acoustic standin g wave in terrestrial gravity. The highest heat transfer augmentation was registered when the heater wire was placed at the acoustic pressur e antinode. In microgravity, the acoustic force was shown to be a prom ising means in maintaining nucleate boiling. (C) 1998 Elsevier Science Ltd. All rights reserved.