Condensation processes of vapor bubbles being injected into subcooled water with and without ultrasonic vibration were recorded by a high-speed video camera to analyze the effects of ultrasonic field on the condensation process and heat transfer of vapor bubbles. Experimental results indicated that the lattice shaped capillary wave formed on the bubble surface increased the condensation heat transfer area greatly and intensified the turbulence in the thermal boundary layer around the vapor bubble

enhancing condensation heat transfer and accelerating bubble condensation in the ultrasonic field. Based on experimental data of relatively large vapor bubbles at liquid subcooling of 15—60 K

empirical correlations were obtained for predicting the condensation heat transfer of vapor bubbles with and without ultrasonic

with deviations within ±30%.