International Journal of Heat and Mass Transfer, Vol.79, 201-211, 2014
Flow characteristics of dual piezoelectric cooling jets for cooling applications in ultra-slim electronics
The flow characteristics of a dual piezoelectric cooling jet (DCJ) were investigated by numerical analysis. The results of various turbulence models were compared with the results of previous experimental reports to develop the reference numerical model. The reference model was determined using a grid-and time-step-dependency test, and the flow characteristics of the DCJ were analyzed using this validated numerical model. The periodic motion of the DCJ that was generated by the piezoelectric disks was observed, and counter-rotating vortex pairs were observed at the orifice. The flow characteristics of the DCJ were dominated by advection of these vortex pairs. Variations in the characteristic velocities were analyzed as a function of the distance from the orifice in the streamwise direction and of the deflection of the piezoelectric disk. Based on these variations, the distance at which a continuous jet developed was investigated, and the jet's flow characteristics were analyzed via spectral analysis. (C) 2014 Elsevier Ltd. All rights reserved.