Entropy generation analysis of mixed-convective flow of magnetohydrodynamic reactive couple stress MWCNT-Ag/C2H6O2 hybrid nanofluid with variable properties in a porous vertical channel

The paper presents the analysis of the mixed convective magnetohydrodynamic (MHD) flow of reactive couple stress hybrid nanofluid with temperature-dependent thermophysical properties in a porous vertical channel. The considered hybrid nanofluid is produced by mixing multi-walled carbon nanotubes ( MWCNT) and silver ([Formula: see text]) nanoparticles in base fluid ethylene glycol ([Formula: see text]) considering the base fluid and the nanoparticles in a thermal equilibrium state. The effect of the magnetic field is considered transverse to the channel walls having constant temperatures. The momentum and energy equations that govern the system are defined using the Darcy-Forchheimer model and are non-nondimensionalized applying relevant dimensionless parameters and solved using the homotopy analysis method (HAM). To analyze the irreversibilities in the system, entropy generation, and the Bejan numbers are defined. Different significant physical parameters arising in the system are considered for the analysis and its effects are scrutinized on the velocity and temperature profiles along with entropy generation. The results show that the velocity and temperature develop in the system with rising variable viscosity and thermal conductivity parameters, and Darcy number whereas it degrades with rising nanoparticle concentration. The rate of entropy generation develops with rising variable viscosity and thermal conductivity parameters and Darcy number whereas it degrades with higher nanoparticles concentration.