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(火积)耗散极值原理给出了新的传热优化的理论依据和评判标准.针对导热固体中包含开口空腔的2种情形(内部产热和外受热),引入了基于(火积)耗散定义的无量纲当量热阻,并以之最小化为目标,对模型进行了构形优化.数值结果验证了本文方法的必要性和可行性.与以无量纲最大热阻最小化为目标的优化结果对比发现,不论哪种模型,当空腔占固体的体积百分比Φ值较小时,2种优化部结果无明显差别,但随着Φ和固体长宽比H/L值的增大,2种优化结果区别越大.固体外受热时的最优空腔,始终比内部产热时的最优空腔更细长.系统的传热性能受热量来源的影响较大,外部加热时的(火积)耗散比内部产热时的(火积)耗散增加了2～3倍,系统传热性能降低.本文方法对相关热设计问题具有一定指导意义.
(Fire Product), the theory of dissipative extremum and the criterion of heat transfer optimization are given.For the two cases (internal heat production and external heat) which contain open cavity in the heat conduction solid, Product), the dimensionless equivalent thermal resistance is defined and the minimization is taken as the goal. The numerical results validate the necessity and feasibility of the proposed method, Compared with the optimized results, it is found that the results of the two kinds of optimization show no significant difference when the volume fraction of cavity occupies a small value of Φ, no matter what model, but with the increase of Φ and the aspect ratio H / L , The greater the difference between the two kinds of optimization results.The optimal cavity when heated outside the solid is always more slender than the optimal cavity when the internal heat is generated.The heat transfer performance of the system is greatly affected by the heat source, (Fire product) dissipation is 2 ~ 3 times higher than that of internal heat production, and the heat transfer performance of the system is reduced.The method proposed in this paper is of some guiding significance for the related thermal design problems.