| Summary: | 碩士 === 國立高雄應用科技大學 === 應用工程科學研究所 === 100 === The Electronic components toward the development of light, thin, short, small, to minimize the components and intensive. The heat flux for unit area of each components is getting better. The piezoelectric fan has the characteristics of small size, ultra-light, low volume and low consume of work. It can substitute the traditional axis fan and placed on the micro electric component for cooling application. This study used the flow visualization technique (Middle Wave Infrared), driven by 110V, 60Hz at the fix amplitude range of piezoelectric fan. The LED uses as the heat source to enhanced the heat performance of the plate-fin heat sink. It is focus on the two piezoelectric fan at side of plate-fin heat sink with height (z/h=0.5, 0.63, 0.75, 0.88, 1), changed pitch of two piezoelectric fans (P/L=0.24, 0.36, 0.59, 0.77) and two way of swing (in-phase, out-of-phase). The nature convection of plate-fin heat sink and heat transfer enhancement of two piezoelectric fans will be discussed.
From experimental results showed, the area of two piezoelectric fans is bigger than single piezoelectric fan in the same heat flux, it can push the air into inner of plate-fin effectively for heat performance rises to 40.91%. The heat performance can be enhanced to 77.39% when the blade of two piezoelectric fan acting in the opposite direction compare to the nature convection. When the two piezoelectric fans are acting in the opposite direction and placed at the side of plate-fin sink, the heat performance will increase follow by the plate-fin heat sink height increase at z/h=0.5, 0.75. In two swing way, out-of phase heat transfer is better than in-phase, the enhance is 1.9%. When the two piezoelectric fans of P/L=0.77 and z/h=0.5, the thermal resistance is 2.128℃/W. The result shows the edge of plate-fin heat sink atz/h=0.5, the heat transfer efficiency rises effectively.
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