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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

VORTEX PROPAGATION IN AIR FLOWS GENERATED BY PIEZOELECTRIC FANS AND THEIR CORRELATION WITH FAN COOLING POWER EFFICIENCY

Get access (open in a dialog) DOI: 10.1615/IHTC16.ctm.022381
pages 3895-3902

摘要

Piezoelectric fans offer a promising alternative to rotary fans due to their simpler structures, less noise, and lower power consumption. We report an experimental and numerical modeling study to help elucidate how the characteristics of the airflows generated by piezoelectric fans relate to their heat transfer performance and cooling power efficiency. Particle Image Velocimetry (PIV) visualization experiments were performed to compare the spatial propagation of vortices generated by the vibrating beams while varying the blade tip velocities. Concurrently, for each tip velocity, we measure the fan power consumption, corresponding heat transfer coefficients and normal forces on flat heated surfaces oriented perpendicular to the beam axis. Our experiments show that there is a threshold blade tip velocity below which no propagating vortices and hence no appreciable air flows in the forward direction are generated. This leads to a precipitous drop in the heat transfer performance. The absence of propagating vortices in this regime is further validated by numerical simulations. The present study improves our understanding of the fluid mechanics of the air flows generated by the piezoelectric fans and their correlation with their heat transfer performance and cooling power efficiency.