Investigation of convective heat transfer augmentation using acoustic streaming generated by ultrasonic vibrations

An investigation of acoustic streaming induced by ultrasonic flexural vibrations is experimentally and numerically presented. The investigation includes acoustic streaming pattern, velocity, and associated heat transfer characteristics. Acoustic streaming patterns visualized using Acetone agree well with the prediction by Nyborg’s theory. Tests of streaming velocity utilizing Styrofoam showed that the acoustic streaming velocity measured prove to be two orders greater than that by Nyborg’s theory. CFD simulations also showed the same order of the velocity as the one measured. By virtue of acoustic streaming, a notable temperature drop of 40 °C was obtained in 4 min and maintained. Tests identifying major heat flow paths indicated that gaps and the vibrating beam serve as major heat flow paths.