Numerical investigations on hydrothermal performance and entropy generation of turbulent flow in channel with turbulators

Purpose The purpose of this study is to investigate the turbulent flow behaviour and heat transfer in a two-dimensional channel equipped with adiabatic turbulators. The study aims to evaluate the influence of turbulator geometry and blockage ratios on thermal and flow performance. Design/methodology/approach A numerical analysis was conducted for Reynolds numbers ranging from 2,000 to 8,000. Four different turbulator shapes (circular, flat, cam and drop) and three blockage ratios (0.25, 0.375 and 0.5) were considered. Three identical turbulators of diameter D were placed in the channel centreline. The governing equations were discretized using the finite volume method and the SIMPLE algorithm was applied for iterative solutions. Turbulence effects were modelled using the low Reynolds number k-e model. Performance indicators including friction factor, average Nusselt number, entropy generation, Bejan number and overall performance factor were analysed. Findings The results showed that turbulator geometry significantly influenced flow and thermal characteristics. Increasing the blockage ratio enhanced the Nusselt number, entropy generation and performance factor, while the Bejan number decreased. Among the examined geometries, the drop-shaped turbulator exhibited the highest performance factor, followed by cam, flat and circular shapes. Originality/value This study provides a comprehensive assessment of different adiabatic turbulator geometries and blockage ratios in turbulent channel flow, offering valuable insights for optimizing thermal performance and energy efficiency in heat transfer applications.