Impact of Conical and Fusiform Turbulators on Heat Transfer Enhancement and Pressure Drop Inside a Double-Tube Heat Exchanger

This study focuses on enhancing heat transfer in a concentric double-tube heat exchanger by incorporating internal turbulators of two distinct geometries: conical and fusiform. The study numerically investigates the impact of these turbulators, placed within the inner tube, on turbulent flow and thermal performance over a Reynolds number range of 4000 to 12,000. A numerical study was carried out using ANSYS Fluent 16.0 software, where the governing equations were solved by the finite volume method. The Realizable k–ε turbulence model was used to capture the effects of turbulence on the flow field. Key performance indicators such as the Nusselt number and pressure drop were analyzed for both configurations. The results reveal that fusiform turbulators provide superior thermal enhancement, increasing the average Nusselt number by up to 34% compared to a smooth tube. However, this enhancement is accompanied by a significant increase in pressure drop across all tested cases, underlining the trade-off between heat transfer improvement and flow resistance. These findings demonstrate the effectiveness of fusiform geometries in improving the thermohydraulic efficiency of tubular heat exchangers.