Influence of input voltage on the structural and fluid flow characteristics and proposed working condition of a micro-blower

Abstract

Several methods are explored for the thermal management of highly packed electronic systems. A forced convection setup called micro-blower is an effective solution for the application of heat removal and it consists of a piezoelectric disc (PED), diaphragm, ring and a top plate. A numerical model is developed to study the influence of input voltage on the micro-blower using COMSOL Multiphysics. The size of the micro-blower selected is 20 × 20 × 3 mm3. Structural characteristics such as Eigen frequency, diaphragm displacement and von Mises stress and output characteristic such as velocity at the nozzle exit, the volumetric flow rate of air, density variation in the fluid domain and pressure gradient of air at the nozzle for various voltage inputs (peak-to-peak voltage, Vp-p) from 5 to 20 V were estimated. The diaphragm displacement of the blower was estimated with various input voltages. An average nozzle velocity of 21.21 m/s was achieved with an average volumetric flow rate of 10.66 × 10−6 m3/s for the voltage input of 20 Vp-p. The von Mises stresses of PED, diaphragm, ring and top plate were 3.38, 6.38, 15.72 and 88.97 MPa and these were within the maximum yield strength of respective components at 20 V and hence the micro-blower design is safe. The proposed Eigen frequency in the ultrasonic range was 21.298 kHz and the proposed input voltage as per the breakdown voltage was 20 V. The results were compared with existing literature data and found promising agreement.