Innovative designs of heat exchangers are crucial to increase the heat transfer effectiveness for the purpose of compactness, energy savings, and emission reductions, among others. In this paper, the thermal-hydraulic performance of turbulent flow inside dimpled and conical tubes under a constant heat flux of 40 kW/m² is numerically investigated using Ansys-Fluent. The proposed novel design and the associated performance analysis were not covered before in the specialized research works of the related literature. Different geometrical and operational parameters (tube diameter ratio/flow modes) are varied to generate key performance indices for the dimpled and conical configurations compared to the traditional smooth heat exchanger case. The model was well-validated against both cases of dimpled and smooth tube configurations. Thermal-hydraulic performance parameters, mainly Nusselt number and friction factor, and performance evaluation criteria (PEC) are investigated for different diameter ratios (DR) of various conical tube heat exchangers of smooth and dimpled surfaces within a range of Reynolds number from 3000 to 40,000. The results for conical tubes with dimples showed considerable enhancements in heat transfer and the overall thermal-hydraulic performance compared to traditional smooth geometrical configurations. The study showed that convergent tube with dimples (DR = 1.5) presents the maximum value of PEC with 29.54% enhancement compared to the smooth geometry with DR = 1. The average-values of PEC over the whole studied range of Re with 8.03% enhancement compared to the smooth geometry at DR = 1, of all studied cases. In addition, convergent tube with dimples (DR = 1.5) presents a maximum percentage of the increase in Nusselt number ratio Nu_r (2.72 at Re = 3000) with 121.4% enhancement compared to the corresponding smooth one. Hence, it can be considered as a promising technique in terms of energy-saving, especially at low values of Reynolds number. It can also be deduced that the newly proposed design of convergent tube HEX with dimples has positive energy efficiency operational characteristics and environmental impacts in terms of potential CO₂ reductions.

换热器的创新设计对于提高传热效率至关重要，以实现紧凑、节能和减排等目的。^{本文研究了在恒定热通量为 40 kW/m 2}的条件下，凹锥管内湍流的热工水力性能。使用 Ansys-Fluent 进行数值研究。相关文献的专门研究工作之前没有涵盖所提出的新颖设计和相关的性能分析。与传统的光滑换热器外壳相比，不同的几何和操作参数（管径比/流动模式）会发生变化，以生成凹坑和锥形配置的关键性能指标。该模型在凹坑和光滑管配置两种情况下都得到了很好的验证。研究了雷诺数在 3000 到 40000 范围内的各种锥形管式换热器的不同直径比 (DR) 的热工水力性能参数，主要是努塞尔数和摩擦系数，以及性能评价标准 (PEC) . 与传统的光滑几何结构相比，带有凹坑的锥形管的结果显示传热和整体热工水力性能有显着提高。研究表明，与 DR = 1 的光滑几何形状相比，带凹坑 (DR = 1.5) 的收敛管呈现出 PEC 的最大值，增强了 29.54%。PEC 在整个 Re 研究范围内的平均值增强了 8.03%与所有研究案例中 DR = 1 时的平滑几何相比。此外，带凹坑的收敛管 (DR = 1.5) 呈现努塞尔数比 Nu 增加的最大百分比 5) 与 DR = 1 的光滑几何相比，PEC 的最大值提高了 29.54%。与 DR = 1 的光滑几何相比，PEC 在整个 Re 研究范围内的平均值提高了 8.03%，即所有研究案例。此外，带凹坑的收敛管 (DR = 1.5) 呈现努塞尔数比 Nu 增加的最大百分比 5) 与 DR = 1 的光滑几何相比，PEC 的最大值提高了 29.54%。与 DR = 1 的光滑几何相比，PEC 在整个 Re 研究范围内的平均值提高了 8.03%，即所有研究案例。此外，带凹坑的收敛管 (DR = 1.5) 呈现努塞尔数比 Nu 增加的最大百分比_r（Re = 3000 时为 2.72）与相应的平滑相比增强了 121.4%。因此，在节能方面，它可以被认为是一种有前途的技术，尤其是在雷诺数较低的情况下。还可以推断，新提出的带有凹坑的收敛管 HEX 设计在潜在的 CO ₂减少方面具有积极的能源效率操作特性和环境影响。