Numerical Investigation on the Heat Transfer Enhancement and Fluid Flow Phenomena Multi-piezoelectric Fans

Abstract

Piezoelectric fan (hereafter named as piezofan) is a thin beam and oscillate in sinusoidal motion when it imposes an alternate current on the piezoelectric material. This motion like a handheld and will induce flow on tip beam. It occupies low power consumption, minimal noise emission, and small and configurable dimensions. In the past, many studies have been conducted on the performance of single piezoefan. The heat transfer benefits over natural convection have been well studied and most applications are focused on electronics cooling. This study is aimed at improving the performance by implementing a multiple number of piezoefans. A numerical approach offered by ANSYS FLUENT 14.5 is shown and comparisons of heat transfer enhancement between single and multiple piezofans is discussed in three-dimension (3D). Different simulation configurations is considered, and the effect of varying the fan amplitude, the distance between each piezofan, and selected configurations of the multi-piezofan are studied to assess the best cooling potential of the fans. The results indicate that the piezofan induced fairly higher air velocity at larger fan’s amplitude, and the nearest point to the piezofan’s tip is the highest velocity. Besides, it was found that the multi-piezofan produced larger vortex formation in the surrounding fluid compared to single piezofan, thus lead to a higher turbulent intensity. In term of cooling effectiveness, the results show that the multi-piezofan in the vertical configuration and placed side by side with the distance of 0.5cm is the most effective way to remove the heat compared to the other tested cases. For the best case, an enhancement in convective heat transfer coefficient exceeding 520% relative to natural convection was recorded. The computational results are validated against previous experimental measurements, with good agreement.