A comparative study on micropolar, Williamson, Maxwell nanofluids flow due to a stretching surface in the presence of bioconvection, double diffusion and activation energy

Abstract Prime aim of current study is to explore the comparative outcomes for mass and thermal transportation of various fluids models namely Newtonian, micropolar, Williamson and Maxwell due to extending surface. This exploration is concerned to the effect of double diffusion and applied magnetic field. The bioconvection may improve the settling of nanoparticles and the double diffusion effects are considered to be more realistic on the part of this work. The mixture of base fluids with nanoparticles and gyrotactic micro-organisms is homogenous. By the implementation of basic conservation laws, the governing partial differential equations are organized which are then reformed into corresponding ordinary differential equations. For the physical insight, Runga-Kutta method with shooting technique is utilized. The controlling parameters of buoyancy ratio, thermophoresis, magnetic field, Brownian movement, Lewis number and Prandtl number are varied in acceptable ranges to evaluate their impacts on temperature, momentum, concentration field and micro-organisms concentration. The notable outcomes indicated that micropolar fluid takes the highest value for velocity and then Newtonian fluid, Williamson fluid and Maxwell fluid in descending order. The results related to different three non-Newtonian nano-fluids with effective heat transfer can find applications in heat transfer processes such as heat exchanger.