Abstract

This study presents a numerical investigation of heat transfer enhancement in a corrugated channel equipped with concave-up obstacles and hybrid nanofluids. The novelty of the present work lies in the combined evaluation of a new obstacle configuration with five different nanoparticles and hybrid nanofluids at two volume concentrations using both single-phase and two-phase numerical models. Numerical simulations were carried out using ANSYS Fluent 19.2 with a two-phase mixture model. Five types of nanoparticles (SiO2, TiO2, Al2O3, ZnO, and CuO) were tested at volume fractions of 1% and 2%, with obstacles optimized in size and position to enhance fluid mixing, over a Reynolds number range of 10,000–30,000. The combined application of concave-up obstacles and nanofluids increased the heat-transfer performance by approximately 244% in terms of percentage enhancement (PE) relative to the baseline corrugated channel using water without obstacles. Despite a considerable pressure drop (up to 15.5 times the baseline pressure ratio (PR)), the performance evaluation coefficient (PEC) indicates an effective trade-off, with the Al2O3–ZnO (50:50) hybrid nanofluid (Case 2) achieving a balanced thermal–hydraulic performance with a PEC of 1.28. These findings demonstrate that the combined application of corrugated channels, obstacles, and hybrid nanofluids is a highly effective strategy for improving heat exchanger efficiency in practical applications.

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