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应用基于离散变截面导热通道的(火积)耗散率最小构形方法,对变截面导热通道单元体进行了构形优化,并与基于定截面导热通道单元体所得优化结果相比较,结果显示:基于变截面导热通道单元体所得平均温差最小值随构形级数的增加而增加并趋近于定值,而基于定截面导热通道单元体所得平均温差最小值随构形级数的增加而减小并趋近于定值.两者的差异是由于第一级构形体的无量纲平均温差不同造成的.提出了普适的提高结构体传热能力的自相似构形优化方法及准则:将无量纲平均温差为α,长宽比(H/L)为β的矩形单元4个组合,热流节点间导热通道截面面积比为2:1,连续组合两次,得到(H/L)为β的下级构形体.若α<(4+4β+β2)/9β,平均温差随着构形级数的增加而增加并逐步趋于定值;若α=(4+4β+β2)/9β,各级构形体平均温差相同;若α>(4+4β+β2)/9β,平均温差随着构形级数的增加而减小并逐步趋于定值.应用基于(火积)耗散率最小的自相似构形优化方法,多级构造后构形体的平均温差趋近于定值.
Based on the minimum configuration of the (fire product) dissipation rate based on the discrete variable cross-section heat transfer channels, the shape optimization of the cross-section heat transfer channel elements is compared with that of the heat transfer channel elements based on the constant cross-section. The results show that : The minimum average temperature difference of the unit body based on the variable cross-section heat conduction channel increases with the increase of the number of formation stages and approaches to a fixed value. On the other hand, the minimum value of the average temperature difference obtained by the unit of the heat conduction channel with constant cross section increases with the increase of the number of formation stages Decrease and close to the fixed value.The difference between the two is caused by the difference of the dimensionless average temperature difference of the first-order structure.A universal self-similar configuration optimization method and criteria are proposed to improve the heat transfer capacity of the structure: (H / L) is the combination of four rectangular elements with dimensionless mean temperature difference α and aspect ratio (H / L) of β, and the cross sectional area ratio of the heat transfer channels between heat flow nodes is 2: 1. (4 + 4β + β2) / 9β, the average temperature difference increases with the increase of the number of conformational stages and gradually approaches the set value. If α = (4 + 4β + β2) / 9β , The average temperature difference at all levels of the same structure; if α> (4 + 4β + β2) / 9β, the average temperature with the conformational order of increase And then gradually decrease to a fixed value.According to the self-similar configuration optimization method based on minimization of (fire product) dissipation rate, the average temperature difference of the multi-stage structure approaches to the fixed value.