Mixed convective magnetohydrodynamic and thermally radiative flow of reactive couple stress MWCNT–Ag/C2H6O2 hybrid nanofluid in a porous vertical channel: Entropy analysis

Abstract

This paper is concerned with the analysis of the mixed convective magnetohydrodynamic (MHD) flow of a reactive couple stress multi-walled carbon nanotube −Ag/C2H6O2 hybrid nanofluid in a porous vertical channel subjected to quadratic thermal radiation along with a uniform inclined magnetic field applied to the channel walls. The flow is driven by the pressure gradient force and the buoyancy force, which is modeled based on the nonlinear Boussinesq approximation. The temperature-dependent reaction rate of the reactant molecule is derived using the Arrhenius law. The momentum and energy equations that govern the system are modeled in consideration of slip and convective conditions. The governing equations are non-dimensionalized by applying relevant dimensionless parameters and are solved using the homotopy analysis method (HAM). To analyze the irreversibilities in the system, the entropy generation number and the Bejan number are defined. Different important physical parameters developing in the system are considered for analysis, and their effects are scrutinized on the velocity and temperature profiles along with entropy generation. The emphasis is given to the concentration of nanoparticles along with the parameters arising due to the reactions of the fluid, buoyancy force, inclined magnetic field, thermal radiation, and porous material. The analysis reveals that the velocity and temperature of the fluid lowers with a higher concentration of nanoparticles, radiation parameter, and Hartmann number, whereas develops for the higher slip parameters and inclination of the magnetic field. The entropy generation rate increases with rising slip parameters and depletes for higher nanoparticle concentration, radiation parameter, Hartmann number, and inclination angle. The irreversibility in the system remains dominant due to heat transfer with higher Frank-Kameneskii and activation energy parameters, Hartmann number, and angle of inclination.