Simulation study of the influence of circular arc vortex generator size on the heat transfer characteristics of fin-and-tube heat exchanger.

Vortex generators (VGs) are extensively utilized in refrigeration equipment to enhance heat transfer performance. This study investigates the geometric optimization of circular arc VGs for improving the thermal performance of fin-and-tube heat exchangers (FTHEs) through numerical simulations. Key geometric parameters (central angle (θ), height (H), inclination angle (α), and attack angle (β)) were systematically analyzed to evaluate their effects on the heat transfer factor (j), friction factor (f), and thermal performance factor (JF). Simulations conducted via ANSYS Fluent 2021R1 revealed that increasing θ enhances vorticity and heat transfer efficiency, with JF rising by 5.2% at θ = 35°. An optimal height of H ≥ 0.8 mm was identified, achieving a 13.0% improvement in j at H = 1.6 mm. While inclination angles below 35° demonstrated minimal impact, inclination angles exceeding 35° significantly intensified turbulent mixing, resulting in an 8.2% increase in j at α = 50°. Higher β value is beneficial to enhance convective heat transfer, achieving 2.0% improvements in JF at β = 30°. This study highlights the critical importance of VG size in optimizing the balance between heat transfer enhancement and pressure loss. These findings offer practical insights for designing energy-efficient FTHEs and advancing sustainable refrigeration technologies.