Analysis of dynamic characteristics and cooling performance of ultrasonic micro-blower

The present study investigated both dynamic characteristics and cooling performance of the ultrasonic micro-blower devices made by Murata™ Manufacturing Corporation. Experiments were performed to investigate associations among input voltage, diaphragm deflection, and jet velocity under varying axial and radial positions. The increasing rate of jet velocity with respect to input voltage was found to decrease obviously as axial distance increased. The experimental results show that transient deflection of the diaphragm vibrated with a frequency of 25.6 kHz for different input voltages. The decreasing rate of the maximum diaphragm deflection with respect to radial position increased sharply as increasing the input voltage. Convective heat transfer coefficient were examined in order to evaluate cooling performance of the micro-blower. The maximum enhancement factor was obtained of approximately 11 times than under natural convection. The Nusselt number was highly dependent on the input voltage and axial distance of the micro-blower. The optimal cooling performance was obtained at the axial position L/D = 20 between the heater and the blower.