Entropy formation in the radiative flow of bioconvective Oldroyd-B nanofluid across an electromagnetic actuator with second-order slip: Active and passive control approach

This research communication provides the impact of heat-mass transmission of Oldroyd-B nanofluid flow having gyrotactic microorganisms past a heated Riga plate. A non-Fourier model is thought to be the one that describes heat and mass fluxes. Second-order slip conditions are introduced into the flow velocity. To develop governing models, a partial differential system is initially built. This system is translated into an ordinary differential model by applying the relevant transformations. Solutions based on convergent series are used to solve the ordinary differential system. Detailed illustrations are presented for the effects of numerous physical factors on nanofluid velocity, thermal, nanofluid concentration, motile microbe density, skin friction coefficient, local Nusselt number, local Sherwood number, motile density microorganism, entropy, and Bejan number profiles. The relaxation and retardation time parameters lead to downturns in the fluid velocity profile. The thermal profile intensifies when enlarging the values of Eckert number and radiation parameter. The chemical reaction parameter and Lewis number play an opposite roles in the nanofluid concentration profile. The bioconvection Lewis number downturns the microorganism profile. Modified Hartmann number causes a reduction in both entropy and Bejan number profiles.