Entropy analysis of Powell-Eyring hybrid nanofluid including effect of linear thermal radiation and viscous dissipation

Hybrid nanofluids are introduced as heat transfer fluids with greater surface stability, diffusion and dispersion capabilities compared to traditional nanofluids. In this work, flow, convective heat transport and volumetric entropy generation in Powell-Eyring hybrid nanofluid are investigated. Hybrid nanofluid occupies the space over the uniform horizontal porous stretching surface with velocity slip at the interface. Effect of viscous dissipation and linear thermal radiation are also included in the simplified model. Mathematical equations for conservation of mass, momentum, energy and entropy are simplified under assumptions of boundary layer flow of Powell-Eyring hybrid nanofluid. Similarity solutions are obtained by transformation of governing partial differential equations to ordinary differential equations, using similarity variables. Keller box finite difference scheme is then adopted to find the approximate solutions of reduced ordinary differential equations. Numerical computations are performed for alumina-copper water (Al2O3-Cu/H2O) hybrid nanofluid and conventional copper water (Cu-H2O) nanofluid. Graphs are produced for velocity, temperature and entropy profiles to study the effect of governing parameters. Skin friction factor and the local Nusselt number are also calculated at the boundary. The notable findings indicate that the hybrid Powell-Eyring nanofluid is better thermal conductor when compared with the conventional nanofluid. The rate of heat transfer at the boundary is greatest for smallest value of the shape factor parameter. The increase in Reynolds number and Brinkman number increases the overall entropy of the system.