Experimental investigation of ultrasonic effect on natural and forced heat transfer in heat sinks

In this study, ultrasonic waves produced by a piezoelectric device were evaluated for their effects on heat transfer and Nusselt number. The study also considered different power levels for thermal heaters with three types of base plates: round pin and extruded plate pin heat sink. The experiment included convective heat transfer tests conducted in both free and forced convection modes. The free convection tests were performed without a fan, while the forced convection tests were carried out with fans of 40 and 60 rounds per minute (RPM). It was observed that ultrasonic vibrations increased heat transfer and improved the efficiency of the system, particularly under laminar flow conditions. In comparison with the no-vibration and no-fan mode (fan = 0 rpm), higher levels of ultrasonic vibration increased efficiency by 2.5 times in the 80-W (W) heater and 60-rpm fan mode.