流体横掠水滴形微针肋热沉流动和传热特性

对传统圆形微针肋进行了优化,设计了3种不同尾角的水滴形微针肋热沉,并以去离子水为工质,实验研究了各热沉流动阻力和传热特性.结果表明:3种尾角针肋中,尾角为60°时减阻效果最好.水滴形针肋的流线型结构可以改善尾部流动分布,推迟流动由层流向过度区流的转变,且尾角越小效果越明显.不同体积流量下,水滴形针肋的最优尾角有所不同.在实验中,雷诺数范围在200～1000内,尾角为60°的水滴形针肋热沉强化换热效果最好.当尾角为30°时,太长的尾部结构受到下一排针肋的影响,造成较大的流动阻力,导致其整体换热效果较差. 

Flow and heat transfer characteristics of drop-shaped micro pin-fin heat sinks with cross flow

Three drop-shaped micro pin-fin heat sinks with different tail angles were designed based on the optimization of traditional round micro pin-fin heat sink.The flow resistance and heat transfer characteristics of the heat sinks were experimentally investigated using deionized water as working fluid.The results show that the micro pin-fin with tail angle of 60° has the lowest flow resistance among the heat sinks.The streamlined structure of drop-shaped micro pin-fins improves the distribution of flow and delays the conversion from laminar to turbulent flow.The smaller the angle, the more obvious the effect.The optimal angle of drop-shaped micro pin-fin is different under different flow rates.The heat sink with tail angle of 60° has the strongest heat transfer coefficient at the corresponding Reynolds number in this experiment (Reynolds number is equal to 200-1000).When the tail angle decreases to 30°, the heat transfer is also enhanced in the tail section of micro pin-fin.However, the flow is affected by the micro pin-fin behind, so the heat resistance is higher than other heat sinks under the same pump power.