Entropy optimization and quartic autocatalysis in MHD chemically reactive stagnation point flow of Sisko nanomaterial

This research article deals with entropy generation and heat generation/absorption analysis for MHD stagnation point flow of Sisko-nanomaterial towards stretchable sheet. Homogeneous-heterogeneous reactions are considered. Nanomaterial comprises thermophoresis and Brownian diffusion effect. Through implementation of second law of thermodynamics the total entropy generation is calculated. In addition, entropy generation for fluid friction, mass transfer and heat transfer is discussed. This study is specially investigated for the impact of homogeneous-heterogeneous reactions with entropy generation subject to distinct flow parameters. The nonlinear systems are computed. Influence of pertinent flow variables on the velocity, entropy, concentration and temperature are discussed. Coefficient of skin friction (velocity gradient) and Nusselt number (temperature gradient) are calculated and examined graphically. The obtained results indicate that entropy rate directly depends upon Brinkman number, diffusion parameter, temperature and concentration difference parameters, magnetic parameter and volumetric entropy number. (C) 2018 Elsevier Ltd. All rights reserved.