Numerical analysis of entropy generation in the stagnation point flow of Oldroyd-B nanofluid

Abstract

In this paper, we introduce a numerical simulation-based study of entropy generation minimization for stagnation point flow of Oldroyd-B nanofluid over a fixed surface. Fluid is magnetohydrodynamic (MHD), incompressible and the impact of viscous dissipation is included in the energy equation. Using transformations, the partial differential system is transfigured into nonlinear ordinary differential equations (ODEs). Likewise, proposed transformations are employed to obtain the dimensionless equation of entropy and Bejan number. Two numerical algorithms bvp4c and NDSolve are utilized to procure values for heat transfer rate and skin friction and to provide validation with preceding literature. The graphical solutions administer an insight into the effects of Brinkman number, Eckert number, Reynolds number, etc., on the velocity, temperature, concentration distribution and entropy production. Results revealed that the entropy rate rises radically with magnetic field parameter, Reynolds number, and Brinkman number whereas opposite trend is noticed for temperature parameter. It’s worth noting that the viscous force of the fluid is stronger than the elastic force for lower Deborah numbers. The findings of the present study will help in understanding the entropy minimization phenomenon coupled with nanomaterials laden flow, which is significant in engineering processes such as microelectronics, micromotors, and clean energy production.