翅片间距对热沉散热功率的影响研究

通过数值模拟手段，对水平放置的热沉在自然对流条件下的散热状况进行了研究．研究发现在热沉的宽度不变的条件下，减少翅片间距（相当于增加热沉上的翅片数目）并不能增加热沉的对流散热功率．通过对比对热沉的数值模拟结果并结合理论分析可知，在水平放置的直翅片热沉中，在翅片间存在一个空气停滞区，该区域内空气几乎不流动，这个特点影响了热沉自然对流散热性能的发挥．随着翅片间距的缩小这个区域面积增加．翅片间距有一最佳数值，在该最佳间距下热沉散热功率最大；翅片间距超过最佳值时，将因减少翅片面积而降低热沉散热功率；翅片间距低于最佳值时，将因减小有效散热面积而降低热沉散热功率．

Three-Dimensional Numerical Simulation of Influence of Fin Spacing on Power of Heat Sink and Heat Dissipation

We study the heat dissipation of the heat sink placing on the level of the natural convection cooling conditions by numerical simalation.It is found that on the conditions of the same width of the heat sink,the power of convection heat dissipation of heat sink can’t be increased by reducing spacing of fins(representing an increase of the number offins of heat sink).A comparion to the numerical simulation results of heat sink and theoretical analysis shows that there is an air stagnation zone in the heat sink of straight fins that placing on the level.The feature that there is almost no movement within the zone affects the play of natural convection of heat sink.With the narrowing of fin spacing the area of this zone increases.There is a best numerical value of fin spacing,and there can be the maximum power of heat sink and heat dissipation under the best spacing.Over the best value,the power of heat sink and heat dissipation will be lowered because of reducing the area of fins;when under the best value,the power of heat sink and heat dissipation also will be lowered because of reducing the effective area of heat dissipation.