Wang Rong, Xie Zhihui, Yin Yong, Chen Lingen
College of Power Engineering, Naval University of Engineering, Wuhan 430033, China.
Institute of Thermal Science and Power Engineering, Wuhan Institute of Technology, Wuhan 430205, China.
Entropy (Basel). 2020 Jun 12;22(6):651. doi: 10.3390/e22060651.
A heat dissipation model of discrete elliptical cylinders with heat generation on a thermal conduction pedestal cooled by forced convection is established. Constructal design is conducted numerically by taking the distributions of thermal conductivity and heat generating intensity as design variables, the dimensionless entropy generation rate (DEGR) as performance indicator. The optimal designs for discrete elliptical cylinders with heat generating are obtained respectively, i.e., there are optimal distributions of heat generating intensity with its fixed total amount of heat sources, and there are optimal distributions of thermal conductivity with its fixed total amount of heat sources. These optimums for minimum DEGRs are different at different Reynolds numbers of airflow. The heat generating intensity can be decreased one by one appropriately in the fluid flow direction to achieve the best effect. When the Reynolds number of airflow is smaller, the thermal conductivity of heat source can be increased one by one appropriately in the fluid flow direction to achieve the best effect; when the Reynolds number of airflow is larger, the thermal conductivity of each heat source should be equalized to achieve the best effect. The results can give thermal design guidelines for the practical heat generating devices with different materials and heat generating intensities.
建立了一种在强制对流冷却的热传导基座上带有发热源的离散椭圆柱体的散热模型。以热导率分布和发热强度分布为设计变量，无量纲熵产率（DEGR）为性能指标，对结构设计进行了数值模拟。分别得到了带发热源的离散椭圆柱体的最优设计，即在固定热源总量的情况下，存在发热强度的最优分布，以及在固定热源总量的情况下，存在热导率的最优分布。这些使DEGR最小的最优解在不同气流雷诺数下是不同的。在流体流动方向上适当逐个降低发热强度可达到最佳效果。当气流雷诺数较小时，在流体流动方向上适当逐个提高热源的热导率可达到最佳效果；当气流雷诺数较大时，应使各热源的热导率相等以达到最佳效果。研究结果可为具有不同材料和发热强度的实际发热装置提供热设计指导。
