Thermal and thermodynamic performance of a tube equipped with angled vane vortex generators: Cfd-based analysis of heat transfer, flow characteristics and irreversibility

This study numerically investigates the first- and second-law thermodynamic performance of a circular tube equipped with novel angled vane vortex generators (AVVGs). The effects of vane angle (α = 10°, 20°, and 30°) and pitch ratio (PR = 5, 10, and 15) on heat transfer, friction loss (f), entropy generation (S˙gen′), exergy efficiency (ηEx), Bejan number (Be), and thermal performance factor (TPF) were analyzed using ANSYS Fluent 2021 with the SST k–ω turbulence model. Simulations were performed for water under turbulent flow conditions within a Reynolds number (Re) range of 12,770–20,824. The results demonstrated that AVVGs significantly enhanced convective heat transfer by intensifying flow mixing and disrupting the thermal boundary layer. The maximum Nusselt number (Nu) of 161.06 was achieved at PR = 5, α = 30°, and Re = 20,824, whereas the highest heat transfer enhancement ratio reached 1.37 compared with the plain tube. Although friction losses increased with decreasing pitch ratio and increasing vane angle, entropy generation due to heat transfer decreased considerably. The minimum total entropy generation (S'gen, tot = 0.1979 W m⁻1 K⁻1) occurred at PR = 5, α = 30°, and Re = 20,824. The highest thermal performance factor of 1.045 was obtained at PR = 15, α = 20°, and Re = 14,378, indicating the optimum thermohydraulic balance. Additionally, empirical correlations with prediction errors less than 7.2% were established for the Nusselt number, friction factor, and TPF. The proposed AVVG design demonstrates strong potential for improving the thermal and thermodynamic performance of compact heat exchanger systems. © Akadémiai Kiadó Zrt 2026.