Experimental investigation of hydrothermal performance enhancement in a corrugated channel equipped with inclined winglets using TiO ₂ / H ₂ O nanofluid

Compact and energy efficient heat exchangers require enhancement techniques that improve heat transfer while maintaining acceptable hydraulic losses. This study experimentally investigates the hydrothermal performance of a corrugated channel equipped with inclined winglets using TiO 2 /H 2 O nanofluid. The proposed approach combines geometric modification through corrugations and winglets with thermophysical enhancement using nanoparticle suspension. TiO 2 /H 2 O nanofluids were prepared at three volume concentrations of 0.5, 1.0, and 1.5 vol. % to evaluate their thermophysical properties and dispersion behavior. Based on the balance between thermal conductivity improvement, viscosity increase, pressure drop penalty, and stability considerations, the 1.0% nanofluid was selected for the detailed hydrothermal experiments. Tests were conducted under turbulent flow conditions at flow rates of 7, 8, and 9 L/min and heat fluxes of 10, 15, and 20 kW/m 2 . The results showed that the corrugated channel with inclined winglets achieved higher convective heat transfer performance than the straight channel due to repeated flow disturbance, secondary flow generation, and thermal boundary layer disruption. TiO 2 /H 2 O nanofluid provided additional thermal enhancement; however, this improvement was accompanied by increased pressure drop due to the higher effective viscosity and intensified flow resistance. The maximum performance evaluation criterion increased from 1.32 for distilled water to 1.58 for TiO 2 /H 2 O nanofluid, with a maximum PEC uncertainty of 9.96%. These findings indicate that the proposed hybrid enhancement approach is promising for compact thermal systems when thermal benefits are balanced against hydraulic and stability limitations.