论文部分内容阅读
(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.针对矩形固体中包含T形开口空腔的传热模型,引入了基于耗散定义的无量纲当量热阻,在系统总体积、空腔体积以及T形腔所占矩形域体积一定的约束条件下,以该当量热阻最小化为目标对模型进行了构形优化.数值结果表明,基于耗散极值原理可以设计出系统传热性能最优的几何结构.修正了文献中无量纲总(最大)热阻的表达式,以其最小化为目标得到了一些与文献结果不同的新规律.将两种热阻指标下的数值优化结果进行了对比分析,发现分别对应两种指标的最优系统结构明显不同,以当量热阻最小化为目标的优化比以最大热阻最小化为目标的优化,可以有效降低传热平均温差,改善系统整体传热性能.空腔自由度越大,系统性能更佳.通过数据拟合,分别得到了当量热阻和最大热阻与3自由度几何参数的优化关联式.
(Fire Product), the theory and criterions of heat transfer optimization are given.For the heat transfer model of rectangular solid containing T-shaped cavity, a dimensionless equivalent heat The model is optimized with the objective of minimizing the equivalent thermal resistance under the constraints of the total volume of the system, the volume of the cavity and the volume of the rectangular domain occupied by the T-shaped cavity. Numerical results show that, The principle of value can be used to design the geometry of the system with the best heat transfer performance. The expression of dimensionless total (maximum) thermal resistance in the literature is revised. Some new rules with different results from the literature are obtained, The results of numerical optimization under different kinds of thermal resistance indexes are comparatively analyzed. The optimal system structure corresponding to the two kinds of indexes is found to be obviously different. The optimization ratio with the objective of minimizing the equivalent thermal resistance as the objective is the optimization with the goal of minimizing the maximum thermal resistance. Which can effectively reduce the average temperature difference of heat transfer and improve the overall heat transfer performance of the system.The greater the cavity degree of freedom, the better the system performance.By the data fitting, the equivalent thermal resistance and the maximum thermal resistance and geometric parameters of 3 degrees of freedom Of correlation.