Numerical investigation of fluid flow and heat transfer in micropolar fluids over a stretching domain

In the present paper, fluid flow and heat transfer for micropolar fluids over a stretching sheet through Darcy porous medium are studied. The heat transfer phenomenon is considered with the isothermal wall as well as the isoflux boundary conditions. The fluid flow and heat transfer phenomena are modeled in the form of coupled nonlinear partial differential equations. The numerical solution is obtained using a nonstandard finite difference approximation on a quasi-uniform mesh. The numerical results obtained by the present approach are compared to those obtained by the Runge–Kutta fourth order method to demonstrate the accuracy of the present method. The numerical results obtained by both methods show excellent agreement. The effect of various physical parameters, namely the Reynolds number, Prandtl number, micropolar material parameters, injection/suction parameter, heat index parameter on bulk fluid speed, temperature distribution, and spin behavior of microstructures are demonstrated and discussed graphically. The simplicity of the finite difference approximation makes the selected technique more significant in the numerical study of micropolar fluid. The boundary layer thickness reduces with the increasing value of injection/suction parameter, Reynolds number, and micropolar parameter. The thermal boundary layer also reduces with the increment in the value of the micropolar parameter, Prandtl number, heat index parameter while microrotation increases with the increasing value of the injection/suction parameter.