Mixed convection and entropy generation of a hybrid nanofluid flow in a tilted channel containing heated blocks

A three-dimensional numerical laminar mixed convection analysis has been examined to investigate thermal transfer, fluid flow, and second law behaviors in an inclined channel with four heated blocks within, submitted under a constant heat flux using Al2O3-Cu water-based hybrid nanofluid as a circulating fluid. Our main purpose is to perform a close-to-reality approach, which leads to results that can be applied in many experimental and industrial fields. This study focuses on the analysis of the effect of Reynolds number (100 <= Re <= 500), Richardson number (0.1 <= Ri <= 2), nanoparticles concentration (0 <= phi <= 0.05), blocks positions, and inclination of the channel (0 degrees <= theta <= 90 degrees) to examine the variation of Nusselt number Nu, temperature gradient entropy S-h, fluid friction entropy S-f, and the number of Bejan Be. Results show that the enhancements provided to the Nu number by elevating previous parameters reached a percentage rate of 3.2% when increasing phi, 12.9% with Ri, and 8.58% with Re; however, the aligned position reveals higher values. There is also an increment in Be number when Ri and Re increase, but in this case, the not-aligned position reveals the highest values. To predict Nu number values, correlations were developed to examine the effects of phi, Ri, and Re on Nu, for both aligned and not-aligned positions.