Investigation and Optimization of the Multiple Piezoelectric–Magnetic Fan System
Date Issued
2015
Date
2015
Author(s)
Tan, Li-Kuang
Abstract
An innovative cooling technology vibrating fans with a piezoelectric-magnetic source is investigated for the thermal management of electronics devices. The objective is to establish a cooling system that uses a piezoelectric-magnetic force as a vibrating source to drive multiple fans for cooling. The vibration driving force is generated by a piezoelectric material actuator coupled with multiple magnetic resonance forces. The cooling performance in terms of thermal resistance is evaluated and measured with different configurations, including the aspect ratio of the fan pitch (P/L) that ranges from 0.167 to 0.333 and the ratio of the gap between the fan tip and the heat sink (G/L) that ranges from 0.0167 to 0.0833 with different fan input powers ranging from 0.15W to 0.25W. The results indicate that multiple piezoelectric-magnetic fan (“MPMF”) system is efficient consuming low power with an improved thermal performance (76.7%) compared with natural convection. In addition, the optimum P/L can be found at 0.233 with different fan input powers. Furthermore, the optimum G/L is 0.05 whereas the optimum P/L is 0.233. The MPMF system can apparently decrease thermal resistance with the advantage of lower power consumption. The cooling performance and heat convection improvement for the MPMF system embedded in a heat sink are also evaluated at different fan tip locations. The results indicate that the fan tip location of the MPMF system at x/Sl =0.5 and y/Sh =0 is an optimum configuration, improving the thermal performance by 53.2% over natural convection condition for the fan input power of 0.1 W. The MPMF system breaks the thermal boundary layer and causes fluctuations inside the fins of the heat sink to enhance the average heat transfer coefficient. Moreover, the relationship between the convection improvement and the Reynolds number for the MPMF system has been investigated and transformed into a correlation line for nine different fan tip locations to provide a means of predicting the cooling performance for the MPMF system embedded in a heat sink.
Subjects
Resonance
The multiple piezoelectric–magnetic fan system
Cooling performance
Thermal resistance
Heat transfer coefficient
Type
thesis
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