Computational heat and mass transfer analysis of magnetized nanofluid flow under the influences of motile microorganisms and thermal radiation

A stagnation-point flow in a two-dimensional (2D) geometry across a nonlinear stretchable surface with varying viscosity and bioconvection is considered. The prominent feature of mass and heat transport is further explained by the instantaneous influences of variable mass diffusivity, chemical reaction, changing thermal conductivity and magnetohydrodynamics. The mathematical model for the above problem is developed in the form of partial differential equations. After applying the proper similarity variables, the PArtial Differential Equation (PDE) are converted to a system of Ordinary Differential Equation (ODE) and are numerically targeted by utilizing a built-in BVP4C technique in MATLAB software. The discussion regarding the problem focuses on determining the crucial values that correspond to the suction and stretching parameters. A parametric analysis of the temperature field, concentration distribution, and axial velocity has been carried out. The numerically produced outcomes show a good fit with results in existing literature. The study underscores the importance of understanding the interplay between various physical parameters in nanofluid flow systems involving bioconvection. Magnetic parameters contribute to an increased axial velocity profile on the other hand diffusive constant parameters λ initially reduce but eventually enhance velocity. Additionally by fixing the values of parameters as 0.1≤Ha≤0.7, 0.3≤α≤1.3, 0.4≤λ≤0.8, 0.2≤Pr≤0.8, 0.1≤Rd≤1.0, ≤θr≤0.5≤Sc≤1.2, and 0.1≤N4 ≤δ≤0.4, it is observed that the higher Prandtl numbers reduce thermal conductivity, leading to a lower temperature profile. Variable viscosity introduces circular streamline patterns, indicating vortex formation and a gradual change in flow curvature from lower to higher viscosity regions. The magnetic field enhances flow stability, producing smoother streamlines and effectively controlling heat distribution in magnetohydrodynamic systems.