基于热交换系数法的散热器等效建模方法研究

针对散热器结构复杂、建模难度大的问题,提出基于热交换系数法利用基座等效整个散热器,简化分析模型.首先由傅里叶定律和牛顿换热公式得到肋片传热的近似解和对流换热热流量,推导出自然对流和强迫对流两种情况下肋片对流换热系数的表达式,并根据能量守恒原则导出基座等效热交换系数关系式.然后用热分析软件Flotherm分别对等效前和等效后模型进行仿真,结果表明热交换系数法是一种行之有效的散热器简化建模方法.该方法同样适用于其它热仿真软件.

Equivalent modeling method of heatsink based on heat transfer coefficient method

To solve the problem that it is hard to model heatsinks with complex structure, the heat transfer coefficient method, which uses its base to replace the whole heatsink, was proposed to simplify the analytical model. First of all, the approximate solution of fins' heat conduction and the heat flow of the convective heat transfer were derived by using Fourier's law and Newton's heat transfer formula. The convective heat transfer coefficient's expressions for the fins were derived under natural convective condition and forced convective condition, respectively. And according to the principle of energy conservation, the heat exchange coefficient of the base was calculated. Then the thermal analysis software Flotherm was used to simulate the pre-equivalent model and post-equivalent model respectively and it is indicated that the heat transfer coefficient method is an effective way to simplify the hearsink model and this method is also applicable to other thermal simulation software.