Optimum tip gap and orientation of multi-piezofan for heat transfer enhancement of finned heat sink in microelectronic cooling

Determination of relative positions and phase angle of dual piezoelectric fans for maximum heat dissipation of fin surface

“…Abdullah et al [14] studied a three-dimensional numerical simulation to determine the optimal arrangement of three piezoelectric fans embedded in a heat sink. The simulated results showed that the heat-transfer performance could be enhanced by 88% compared with that obtained using natural convection by arranging the fans in a vertical direction and setting the normalized tip clearance for each fan as 0.17.…”

“…[14,15], the authors obtained the optimal arrangement among a limited number of test cases; however, they did not apply the optimization technique to the design analysis.…”

Mechanism of enhancement of heat transfer for plate-fin heat sinks with dual piezoelectric fans

“…Under optimal conditions, the cooling performance was at resonance and oriented normal to the heat source, resulting in an enhancement 3.75 times in the heat transfer relative to natural convection alone. Abdullah et al [18] presented an experimental analysis of the effects of the tip gap and the amplitude of vibration of piezoelectric fans on the heat-transfer characteristics of finned heat sinks and concluded that the best result occurred at large amplitudes and with a minimum tip gap. Choi et al [19,20] investigated the unsteady flow fields around single and dual vibrating fans in a free stream, and concluded that the performance of dual piezoelectric fans vibrating in counter-phase is invariably superior to dual piezoelectric fans vibrating in phase unless the distance is too small.…”

Moving-orientation and position effects of the piezoelectric fan on thermal characteristics of the heat sink partially filled in a channel with axial flow

“…The increase in the oscillating frequency and amplitude of piezoelectric fan could also enhance the heat transfer rate linearly. Abdullah et al [14] observed the effect of piezoelectric fan on the heat transfer of finned heat sink. Multiple piezoelectric fans were placed between the fins of heat sink vertically or horizontally.…”