标题: 摇摆式散热片之热传性能研究
A Study of Heat Transfer of a Heat Sink with Swinging Fins
作者: 李毓晨
Yu-Chen Lee
傅武雄
Wu-Shung Fu
机械工程学系
关键字: 摇摆、散热片;fin . heat sink
公开日期: 2000
摘要: 振动发热物体是一个有效地增加热传递率的方法,散热鳍片摆动速率较大时,会在鳍片上表面与下表面交错形成回流区和再附着区,并逐渐往下游迁移,使得原本附着在鳍片上之速度和温度边界层受到扰动而被破坏和缩小,热传效果会提升。
本文即以实验对自制之摇摆式散热片进行热传分析,此动态散热鳍片是以厚度15μm之极薄铜片为鳍片的材质,使空气流经鳍片时能诱导鳍片在流场中振动,并与传统固定式之散热片作比较,但因实验中所有种类的摇摆式散热片其热传效能并未如预期中的理想,故再以数值模拟辅助分析实验结果,讨论动态散热片效果不理想的可能原因,结果发现实验中摆动式散热片的散热效果反而比传统固定式散热片差的原因,是因为非一体成型与鳍片过薄对散热性能的负面影响,已经盖过鳍片摆动对散热性能的正面影响,故热传效果无法有效提升。
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.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT890489037
http://hdl.handle.net/11536/67536
显示于类别:Thesis