Parametric study and design optimization of finned tube heat exchangers for enhanced indirect evaporative cooling

Abstract

This study presents a comprehensive computational analysis, parametric study and optimization of a finned-tube heat exchanger (FTHE) integrating with Multi-Directional Wind Tower (MDWT) in Indirect Evaporative Cooling (IEC) applications aimed at improving thermal performance while minimizing pressure drop (Δp). A parametric investigation was conducted using validated computational fluid dynamics (CFD) simulations to assess the effects of fin height (hf), fin thickness (tf), and fin spacing (Sf) on thermal performance and flow resistance. Key trends revealed that Sf influences the heat transfer coefficient (h) non-linearly, while hf shows diminishing returns beyond a critical value. tf had a minor effect on Δp but improved fin efficiency (ηf), especially at higher Reynolds numbers (Re). A performance indicator was defined as the ratio of Nusselt number Nu and Euler number (Eu) to simultaneously enhance heat transfer and reduce flow resistance. A MATLAB-based optimization algorithm was then implemented to determine the configuration exhibiting the highest performance score. The optimal design was found to have a hf of 4 mm, tf of 1 mm, and Sf of 2 mm, achieving a Nu of 195.57, Eu of 4.48, and Nu/Eu of 43.61. The optimized geometry design observed 88.32 % increment in Nu in comparison to the base case for model validation. Correlation models are developed for Nu and Eu using log–log linearization technique and achieved high accuracy of R2 of 92.47 % and 96.58 %, respectively. It offers reliable predictions for future design efforts. The findings provide practical insights into integrating FTHE in IEC with balanced thermal and hydraulic performance.