Abstract
This work deals with the study of Darcy-Forchheimer flow of micropolar ferrofluid on a porous and dynamic (stretching/shrinking) sheet under the influence of thermal radiations subjected to both suction and injection. The effects of the external electric and magnetic fields are considered as well. Water is used as a base fluid and Fe3O4 (iron oxide) as electro-magnetite nanoparticles. The mathematical equations developed in this study are based on the Cattaneo-Christov model consisting of coupled nonlinear partial differential equations. These equations are transformed into a set of coupled ordinary differential equations (ODEs) by using similarity transformations. These ODEs are solved by applying the standard mathematical technique of homotopy analysis (HAM). The effects produced by different parameters on the velocity, micro-rotational velocity and temperature profiles are shown graphically for positive as well as negative mass transfer flow and for both stretching and shrinking cases. It has been observed that the velocity profile increases (decreases) with the increasing electric field strength and microrotation parameter during the stretching (shrinking) of the surface in both suction (S > 0) and injection (S < 0) cases. Furthermore, similar results has been observed for the velocity profile with the increasing inertial coefficient, porosity, magnetic and boundary parameters during flow over the stretching (shrinking) surface for both S > 0 and S < 0. The micro-rotational velocity increases with higher values of microrotation parameter for stretching, while decreases for the shrinking of the surface. The temperature profile displays an increasing trend with the increasing values of heat energy source and sink terms and thermal radiation parameter for stretching as well as shrinking of the sheet for S > 0 as well as S < 0. The temperature profile also changes with the variation in thermal relaxation parameter and Prandlt number.