Entropy generation analysis of mixture nanofluid (H2O/c2H6O2)–Fe3O4 flow between two stretching rotating disks under the effect of MHD and nonlinear thermal radiation

Abstract

ABSTRACT The flow of water and a mixture of water–ethylene glycol as a base fluid and Fe3O4, as a nanoparticle between two stretching rotating disks, are investigated. The entropy generation has been modelled by the second thermodynamic low. The thermal irreversibility, fluid friction irreversibility and joule dissipation irreversibility are considered in this model. The Lorentz force and Joule heating effect due to a magnetic field and nonlinear thermal radiation have been considered in governing equations. The fifth-order Runge–Kutta method is applied to solve the nonlinear governing equations. The results are compared with those of the previously published papers and show excellent agreement. The effects of Radiation parameter, magnetic field, Brinkman number and volume fraction of nanoparticles on total entropy generation and Bejan number are investigated. Also the effects of the variable parameter on the velocity and temperature profile, skin friction coefficient and Nusselt number are examined. The results are compared with those of the mixture base fluid (water–ethylene glycol) and pure water.