Numerical simulation of unsteady MHD bio-convective flow of viscous nanofluid through a stretching surface

Abstract

The current flow model is prepared to explore the characteristics of heat and mass transfer through a time-dependent bio-convection slip flow of viscous nanofluid moving over a porous radiative stretched surface model. The outset of bio-thermal convection in a suspension comprising gyrotactic microorganisms and nanoparticles is considered along with radiation and velocity slip. The presence of these nanoparticles and their motion within the nanofluid gives rise to thermophoresis as well as the Brownian motion phenomena and the consideration of these aspects in the model gives realistic results. Moreover, the present model includes the collective influence of the aligned magnetic field, heat source, and mass suction on the boundary. The similarity analysis has been carried out to transform the basic model equations into nonlinear dimensionless ordinary differential equations (ODEs) which are solved numerically using the bvp4c technique in MATLAB. Some reasonable values have been assigned to the flow parameters based on the above different conditions which provide various graphical results. Certain finding states that velocity and temperature respectively decrease and increase as the aligned magnetic field angle is scaled up, whereas the nano particles concentration strengthens with the amplifying values of convection diffusion and thermophoresis parameter and slumps with the rising values of Brownian motion parameter and Schmidt number respectively. Moreover, the concentration of microorganism and nano particles diminishes with the rising values of Schmidt number, as well as the improvement of convection diffusion parameter and Schmidt number magnifies the Sherwood number. The local density of motile microorganisms reduces with the improvement of stretching parameter and bio-convection Schmidt respectively. The obtained results have been validated by comparing them with the published literature.

Keywords

• Stretched surface
• Gyrotactic microorganisms
• Aligned MHD
• Nanofluid
• Heat source
• Thermal radiation