Heat Transfer Characteristics of Heat Sinks with Confined Impinging Jet

• Main Authors: Shung-Ming Chao, 趙上茗
• Other Authors: Hung-Yi Li
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/70088306017216007111

碩士 === 華梵大學 === 機電工程研究所 === 92 === Air cooling possesses the characteristic of convenience, simplicity, high reliability, and low cost. Jet impingement cooling among them has the advantage of local cooling and fast heat transfer. It is widely applied to control the temperature of electrical equipments. The cooling method usually needs to be combined with heat sinks to achieve the highest efficiency. To design the geometrical shape properly becomes the determinant factor for increasing the heat transfer and decreasing the working temperature. In this thesis, an experimental method by infrared thermal image camera is used to measure the temperature of the heat sinks. The optimization of the heat transfer of the heat sinks within confined space is investigated. The optimal design at a specific impinging velocity is obtained by changing the style of the heat sink, the width and the height of the fin, and the distance between the nozzle and the tip of the fin for a controlled heating rate. The research reveals that the heat transfer of the pin fin heat sink is better than that of the plate fin heat sink under the same condition. Increasing the velocity of the impingement jet can increase the heat transfer of the heat sinks. However, the enhancement of heat transfer decreases gradually as the impinging velocity increases. The heat transfer increases with increasing fin width. The effects are distinct at high impinging velocity. Increasing the fin height to enlarge the heat transfer area can increase the heat transfer rate, too. However, the effects are not conspicuous as those caused by changing width. The effects of the impinging distance depend on the impinging velocity. The optimal impinging distance increases as the velocity increases.