| Summary: | 碩士 === 國立交通大學 === 機械工程系 === 89 === It is an effective way to enhance the heat transfer rates by oscillating a heat source. For fins swinging in a flow, the velocity and thermal boundary layers may be contracted and disturbed as the fins swing with a large speed, and the heat transfer rates are remarkably affected by the swinging speed and amplitude of the fins.
This study investigates the heat transfer ability of heat sinks with swinging fins experimentally, those finned heat sink were made by installing extremely thin copper fins (15μm) in the heat sink, and these fins may swing back and forth in a flow as the fluid flows through them, compared the heat transfer performance with the heat sink with fixed fins. But in the results of the experiments, the heat transfer ability of all kinds of the heat sinks with swinging fins is not as good as expected. So the present study discuss the results of the experiments further by numerical simulations, the results show that the reason of the worse heat transfer ability of heat sink with swinging fins is that the contact resistance between the interfaces of the fins and base of the heat sink, and another reason is that the fins are too thin to transfer enough heat from base to fins. The negative influence of those two reasons on heat transfer covers up the positive one of the swinging fins. So the heat transfer performance of the heat sinks with swinging fins is not better than that of the heat sinks with fixed fins in the experiments.
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