Effect of changing geometric parameters in an elliptical tube and fin heat exchanger with alternating tube arrangement

Finned tube heat exchangers are fundamental components in thermal and fluid engineering, with extensive applications in oil and gas industries, power plants, and air conditioning systems. Due to the inherently low convective heat transfer coefficient on the gas side within heat exchangers, numerous efforts have been made to enhance heat transfer on the air side through innovative fin designs and analysis of geometric parameters. This paper presents a numerical simulation of flow and forced convection heat transfer in a fin-and-tube heat exchanger with elliptical tubes and a staggered tube arrangement using ANSYS Fluent software, aiming to compare the effects of three dominant geometric parameters (fin thickness, longitudinal pitch, and transverse pitch) on thermohydraulic performance to simultaneously achieve high heat transfer and low pressure drop. The results indicate that among the studied parameters, only increasing the transverse pitch leads to simultaneous improvement of both criteria. Increasing the transverse pitch from 35 mm to 50 mm enhanced the heat transfer rate while reducing the pressure drop. In contrast, increasing the fin thickness had an adverse effect, and increasing the longitudinal pitch exhibited a dual effect (positive on heat transfer but negative on pressure drop). These findings suggest that in the design process of such heat exchangers, the transverse pitch can serve as an influential and cost-effective lever to simultaneously achieve thermal and hydrodynamic objectives.