“水滴”型微针肋流动与传热特性数值研究

Numerical study of flow and heat transfer for "droplet" type fin-fin heat sink

基于圆肋尾部流动传热强化的思想,对传统圆肋进行优化,进而设计出了新型的"水滴"型微针肋。采用Fluent模拟软件对不同角度"水滴"型针肋侧壁及整体流动传热特性进行了模拟分析。结果表明:α>90°时,流动没有显著改变,边界层涡依旧发生脱落;而当α<60°后,针肋尾部逆压梯度较小,边界层涡脱离现象消失;适当的"水滴"型结构,可以避免针肋尾部涡脱落造成的阻力损耗;将针肋尾部对流传热较弱的区域由固体导热代替,同时将传热表面向流体主流区拓展,传热效果明显强化;模拟条件下,45°<α<60°时,针肋热沉综合性能最好。

signed a novel ＂droplet＂ type micro pin-fin heat sink.Flow and heat transfer characteristics of fin side and overall heat sink for different ＂droplet＂ type pin-fin tail angles have been numerically analyzed.The results showed that： the flow did not change significantly,and the boundary layer vortex shedding still occurred,when α90°;while α 60 °,boundary layer vortex no longer separated for the smaller adverse pressure gradient of tail flow.Appropriate ＂droplet＂ structure could avoid the pressure loss caused by vortex shedding.The weak convection region was replaced by solid thermal conductivity,and the heat transfer surface was extended to the mainstream region,thus it would lead to enhancement of heat transfer effect obviously.＂Droplet＂ type pin-fin heat sink had the best comprehensive property at current simulation conditions,when 45°α 60 °.