Effect of varying passive interrupted geometrical techniques to implement novel parametric assessment of improving thermal-hydraulic performance in 3D pipe

This study investigates the hydrodynamic and thermal performance of pipes incorporating passive geometric modifications, focusing on optimizing fluid flow dynamics and heat transfer efficiency. A computational analysis evaluates turbulent flow behavior and heat exchange in three-dimensional pipe geometries under constant heat flux conditions, spanning Reynolds numbers from 1000 to 14,000. The research employs a single-phase, water-based thermo-hydrodynamic framework to assess Insert Twisted Tape (ITT), Corrugated Ring Diameter (CRD), and Dimple Surface Diameter (DSD) pipe configurations. Results indicate that the maximum difference between the numerical simulations and the empirical equations for Nu is 7.9%. Similarly, the maximum difference in the friction factor (f) between the two approaches is 6.5 %. Also, using different passive geometric designs significantly enhance the Nusselt number (Nu) and overall thermal performance compared to smooth pipes. Structural modifications induce secondary vortical flows and amplify turbulence, disrupting thermal boundary layers and improving heat transfer. Performance evaluation criteria exceeding unity confirm the superiority of these geometries over conventional smooth channels. In addition to enhancing heat transfer rates, the study highlights the impact of passive geometric configurations on pressure drop and energy consumption. While dimpled and corrugated designs exhibit superior heat transfer capabilities, they also generate higher pressure drops due to increased surface roughness and fluid interaction. However, the substantial thermal performance improvement often compensates for the additional pumping power required. A comparative performance analysis based on the overall thermal performance factor (PEF) of the evaluated geometries indicates that the dimpled surface design (DSD) achieved the highest PEF value of approximately 1.8. The corrugated (CRD) and twisted tube (ITT) configurations followed, with PEF values of 1.77 and 1.61, respectively. The study concludes that selecting the most suitable configuration depends on the desired balance between thermal enhancement and energy expenditure, with dimpled designs being the most effective in scenarios prioritizing heat transfer.