Entropy optimization for flow of second-grade nanomaterial

Here we address entropy generation in mixed convective magnetohydrodynamics chemically reactive flow of second-grade nanomaterial over a heated stretched sheet. Second-grade nanomaterial is considered electrically conducting. Characteristics of heat transfer are discussed through nonlinear heat flux, viscous dissipation and heat source/sink. Novel behaviors of thermophoresis and Brownian diffusion are also accounted. Nonlinear flow expressions are first converted into ordinary differential one through appropriate transformations. Optimal homotopy method is used for solution development. Impacts of different flow variables on the velocity, entropy generation rate, Bejan number, temperature and concentration are discussed through graphs. Surface drag force and gradient of temperature are graphically discussed. Present results are also compared with published literature. Velocity and temperature fields monotonically boost up via higher second-grade parameter. Entropy rate increases via larger Brinkmann number and magnetic parameter. Bejan number is maximum for (Br = 0) and then it gradually decays for increasing the value of Brinkmann number.