Does the Interaction Between Fin Pitch and Vortex Generator Geometry Control the Overall Heat Exchanger Performance?

This study numerically evaluates heat‐transfer enhancement in compact fin‐and‐tube heat exchangers by combining fin‐pitch optimization with surface‐mounted vortex generators (VGs). A preliminary scan of two fin pitches (15 and 25 mm) identifies 15 mm as the superior baseline, delivering ~7.4% higher convective coefficient. Building on this geometry, two VG shapes—triangular and semi‐cylindrical—are assessed for thermal‐hydraulic performance using validated 3‐D CFD. The semi‐cylindrical VG consistently outperforms the triangular one, increasing heat transfer by > 17% under comparable conditions owing to stronger, more persistent longitudinal vortices near the heat‐transfer surfaces. The model reproduces the published benchmarks with deviations < 5.5%. Additional parametric tests across Reynolds number and inlet‐air temperature confirm the robustness of these trends. Overall, coupling an optimized fin pitch with a semi‐cylindrical VG yields a compact exchanger with markedly improved heat‐transfer performance, offering practical guidance for high‐efficiency HVAC and automotive applications.