The Effect of Channel Arrangement on the Performance of Dual Piezoelectric Fans

Piezoelectric fan is widely used in electronic products heat dissipation. Channel arrangements affect the cooling performance. Flow and temperature distributions in five schemes: (1) large space, (2-4) top opening channels with different restricted extents, and (5) channel with four enclosed sides) were investigated. Time average velocity distributions reveal the flow characteristics of two high-speed cooling fluids forming from blade roots. The cooling fluids gradually converge in the middle of blade tips and disperse downstream. Scheme (5) has the highest velocity of 8 m/s due to the strongest sucking and driving effects of negative and positive pressure zones. Air ventilation rates of schemes (1-5) cover the range from 1.21 x 10-3 to 2.07 x 10-3 m3/s. For schemes (1-4), the maximum ventilation always comes from top boundary, with the percentage above 80%. Among all schemes, the maximum temperature of scheme (1) is lowest, which is 467.401 K. However, the highest space-time average heat transfer coefficient is obtained in scheme (1), up to 54.02 W/(m2 center dot K). The value decreases sequentially in schemes (5, 2, 4 and 3). Mismatch between main flow velocity and heat transfer coefficient highlights the three-dimensional sucking effect of piezoelectric fan.