A three-dimensional double-sided delta-wing (D-T-W) shape design problem is studied in the present work to estimate the optimal wing-width ratio $w/W$, height-pitch ratio $c/P$, and attack angle $\alpha$ of D-T-Ws in a double-pipe heat exchanger for the target thermal performance factor using the Levenberg–Marquardt method and CFD-ACE+ software package. Our solutions indicate that a reasonable discrepancy exists between the numerical and experimental values of $\mathit{Nu}$ and $f$ because they are always within $\pm 5\%$ and $\pm 9\%$ errors, respectively. Then, three design cases, A, B, and C, based on a design template with $L=100\mathrm{mm}$, are conducted numerically, and the resultant $\eta$s are justified by comparing them with the plain tube (i.e., no inserts), longitudinal strip insert, and D-T-W tape insert design heat exchangers. The results reveal that considering $w/W$, $c/P$, and $\alpha$ as the design variables can indeed improve thermal performance factor $\eta$. Finally, the optimal geometries of D-T-W tape inserts for cases A and B are used on a regular length $L=2000\mathrm{mm}$. The results illustrate that design B with $w/W=0.65,c/P=0.51$, and $\alpha =72.90\mathrm{deg}$ is considered as the optimized design of this work; its thermal performance factors can be further improved by 4.6%, 2.5%, and 3.3% for $\mathit{Re}=5569$, 10,630, and 14,540, respectively.

在本工作中研究了三维双面三角翼（DTW）形状设计问题，以估计最佳翼宽比 $w/\mathrm{w\; ^}$，高音高比 $C/P$和攻角 $\alpha$使用Levenberg-Marquardt方法和CFD-ACE +软件包在双管式换热器中的DT-Ws达到目标热性能因子。我们的解决方案表明，在数值和实验值之间存在合理的差异。$\mathit{怒江}$ 和 $F$ 因为他们总是在 $\pm 5％$ 和 $\pm 9％$错误。然后，基于带有以下内容的设计模板，三个设计案例A，B和C：$\mathrm{大号}=100\mathrm{毫米}$，通过数字进行，结果 $\eta$通过将它们与普通管（即，无插入件），纵向条形插入件和DTW带状插入件设计的热交换器进行比较来证明它们的合理性。结果表明，考虑到$w/\mathrm{w\; ^}$， $C/P$， 和 $\alpha$ 因为设计变量确实可以改善热性能系数 $\eta$。最后，在常规长度上使用案例A和案例B的DTW磁带插入件的最佳几何形状$\mathrm{大号}=2000\mathrm{毫米}$。结果表明，设计B具有$w/\mathrm{w\; ^}=0.65，C/P=0.51$， 和 $\alpha =72.90度$被认为是这项工作的优化设计；其热性能因子可以进一步提高4.6％，2.5％和3.3％$\mathit{关于}=5569$，10,630和14,540。