Pulsating flow of a micropolar-Casson fluid through a constricted channel influenced by a magnetic field and Darcian porous medium: A numerical study

•Numerical investigation of pulsatile MHD flow of non-Newtonian fluid, exhibiting both micropolar and Casson characterizations fluid, in a constricted channel following Darcy’s law is carried out.•The vorticity-stream function approach, together with the finite difference method, is used to solve the governing equations.•The effects of the flow controlling parameters on the axial velocity, micro-rotation velocity, wall shear stress are studied.•The streamlines and vorticity graphs are displayed for the entire channel. The behavior of the pulsatile flow of non-Newtonian micropolar-Casson fluid in a constricted channel influenced by Lorentz force following Darcy's law is examined. The governing model of the problem is transformed into the vorticity-stream function formulation and numerically solved using a scheme based on the finite difference method. Impacts of numerous flow controlling parameters including the Hartmann, Strouhal, porosity, Casson fluid, and micropolar fluid parameters on the wall shear stress (WSS), axial velocity, and micro-rotation velocity are presented graphically and discussed. The WSS is found to increase with rising values of any of the Hartman, Casson fluid, and micropolar fluid parameters. The WSS decreases with rising values of the porosity parameter. The Hartman number is found to have a significant impact on the flow separation region, as well. The velocity profiles are parabolic at all the axial locations. At the constriction throat, the maximum value of the velocity is identified.