Impact of Brownian motion and thermophoresis on entropy generation in a cavity containing microorganisms

Abstract

Abstract The present article examined the impact of Brownian motion and thermophoresis on entropy generation of bioconvective flow in a porous cavity filled with nanofluid and gyrotactic microorganisms. Darcy’s Boussinesq approximation is implemented to tackle the porosity term in the momentum expression. The governing partial differential equations (PDEs) are highly nonlinear and are nondimensionalized through the suitable similarity constraints. Finite difference method (FDM) is employed to solve the transformed PDEs. The reaction of entropy generation against various quantities like, Brownian movement (Nb), thermophoresis (Nt), Lewis number (Le) and Schmidt number (Sc) is explored and visualized. The entropies by heat transportation and mass transmission of microorganisms are also focused. An improvement in Lewis number, Schmidth number and Brownian motion corresponds a gradual decline in the local entropies by heat transportation, mass transfer of microorganism and local Bejan number. Thermophoretic force accelerates the distribution of local Bejan number.