Enhancing Hydrothermal Performance of Dimpled Tubes: Investigating the Impact of Different Dimple Sizes and Distribution along the Tube

The main purpose of this research is to optimize the hydrothermal performance of a dimpled tube by augmenting the surface area for heat transmission and thermal layer cracking. To achieve that, the impact of different dimple diameters and their distribution along the dimpled tube was investigated numerically using the ANSYS Fluent 2022 R1 software by considering two models, A and B. Both models consist of three regions; the first, second, and third have dimple diameters of 3, 2, & 1 mm, respectively. Model A included an in-line dimple arrangement, while model B involved a staggered dimple arrangement. The finite volume method (FVM) was used in the modeling techniques to address the turbulent flow problem, which ranged in this investigation from Re of 3000 to 8000. The cooling fluid used in this investigation is water, which concentrated primarily on single-phase flow conditions. The investigation results revealed that as the Re increased, all analyzed models showcased higher. A reduction in pressure drops, thermal resistance, Nu, and overall performance standards. Crucially, compared to the traditional model, both suggested models demonstrated improved heat transmission capacities. Within all the models examined, the tube with dimples in (model B) as staggered showed the greatest enhancement in the Nu, which was almost double that of the conventional type. Model A and Model B have respective average total performance criteria of 1.23 and 1.34.