The impact of the movement of the gyrotactic microorganisms on the heat and mass transfer characteristics of Casson nanofluid

This article focuses on analyzing the impact of the movement of gyrotactic microorganisms on the heat and mass transfer characteristics of Casson nanofluid flowing between divergent. Further, the analysis is performed through simulation to have a better understanding of the impact. Since the microorganisms are self-propelled, they move on their own in the nanofluid due to the concentration gradient and stabilize the nanoparticle suspension. This movement of microorganisms constitutes the formation of bioconvection. Further, the random motion of nanoparticles gives rise to two major slip mechanisms termed thermophoresis and Brownian motion. The mathematical model comprising these effects is designed using partial differential equations that are converted to ordinary differential equations with the help of suitable similarity transformation. The resulting system of equations is then solved using the differential transformation method and the outcomes are interpreted through graphs. It is indicated that the nanoparticle concentration and the motile density profiles increase with the increase in Schmidt number and also, the concentration profile is found to be increasing for higher Brownian motion parameter and lower thermophoretic parameter. The simulations performed through the finite element method portrayed that the heat flow in the diverging channel is occurring along the isothermal planes.