A numerical investigation of a curved trapezoidal-corrugated channel with E-shaped baffles is conducted for thermal-hydraulic performance and flow behavior involving the use of single and hybrid nanofluids. This investigation introduces a unique integrated methodology for enhancing heat transfer efficiency by simultaneously combining geometric modifications and optimizing coolant utilization. To simulate turbulent, single-phase flow in three-dimensional corrugated channels, a computational model has been developed. The model considers a Reynolds number (Re) range of 5 × 103≤Re ≤ 35 × 103 and implies a uniform heat flux of 1000 W/m2. A commercial software, Ansys fluent was used in order to simulate the fluid flow by setting the inlet temperature at 300 K and velocity according to the Reynolds number. The continuity equation, momentum equation, and energy equations are discretized using a second-order upwind method. The equation's residual has been assigned a value of 1 × 106 for absolute criteria. The study evaluates the thermal-hydraulic performance of single nanofluids (Al2O3/water, CuO/water, SiO2/water) and hybrid nanofluids (Al2O3-Cu/water, TiO2-SiO2/EG-water) at varying volume fractions (1%≤φ ≤ 5%). Additionally, the investigation examines the effects of corrugations, baffles, and geometric parameter: blockage ratio (BR = 0.10, 0.15, 0.25). The findings demonstrate that the effects of baffles and corrugations can lead to the creation of vortex flow and greater turbulence, which can promote heat transfer enhancement. Various nanofluids demonstrated a significant rise in the Nusselt number, ranging from 35% to 60%, when compared to water in a curved corrugated channel. Additionally, a lower BR resulted in a smaller but still notable gain of 15%-19%. An effective heat exchanger that results in a significant energy dissipation is measured by the energy ratio (ER). The use of corrugated channels with narrow baffles has been found to consistently outperform smooth channels in terms of thermo-hydraulic parameters, leading to enhanced heat transfer. Using BR = 0.10 over 0.25 resulted in an increase in ΔP, HTC, and ER of 48.44%, 18.71%, and 45.86%, respectively. The implementation of a hybrid nanofluid consisting of 1% (20% TiO2-80% SiO2)/(60% Water-40% EG) volume fraction in a curved corrugated channel with baffles resulted in a significant improvement of 36.49% in thermal performance. This finding suggests that the aforementioned nanofluid composition and design parameter, characterized by a blockage ratio of 0.10, are the most effective in enhancing thermal performance.
Keywords: Baffles; Curved corrugated; Heat transfer; Hybrid nanofluid; Thermal-hydraulic; Vortex generation.
© 2024 The Authors.