ISSN Online: 2377-424X
ISBN Print: 0-85295-345-3
International Heat Transfer Conference 10
EFFECT OF ULTRASONIC EMISSION ON BOILING AND NON-BOILING HEAT TRANSFER IN NATURAL AND FORCED CIRCULATION SYSTEMS
Resumo
The present study was undertaken to clarify the effects and mechanisms of the ultrasonic waves on boiling and non-boiling heat transfer in natural and forced circulation systems. Experiments were conducted in non-boiling convection, nucleate boiling and film boiling regions. The results indicated a significant increase in heat transfer rate caused by an application of the ultrasonic waves both in single-phase convective and film boiling regions, whereas heat transfer was not so much enhanced in nucleate boiling, particularly at high heat fluxes with low liquid subcoolings. The primary mechanism to increase heat transfer rate has been made clear to be a highly improved convective heat transfer caused by acoustic streams.