Pool boiling under ultrasonic wave

Subcooled pool boiling heat transfer was experimentally studied under different ultrasonic intensity and emission distance. The results indicate that the ultrasonic wave can enhance the heat transfer under natural convection and initial boiling region and has a benefit to pool boiling heat transfer under high heat ux. Moreover, the closer emission distance to the heat surface is and the greater the ultrasonic intensity is, the better the enhancement heat transfer is. The mechanism of enhancement heat transfer under natural convection and initial boiling region is the cavitation influence, and the acoustic flow induced by the ultrasonic wave becomes domain mechanism under high heat flux pool boiling. Two correlations were proposed to predict the heat transfer coefficient under the two corresponding conditions.