Micromagnetorotation of MHD Micropolar Flows

Abstract

The studies dealing with micropolar magnetohydrodynamic (MHD) flows usually ignore the micromagnetorotation (MMR) effect, by assuming that magnetization and magnetic field vectors are parallel. The main objective of the present investigation is to measure the effect of MMR and the possible differences encountered by ignoring it. The MHD planar Couette micropolar flow is solved analytically considering and by ignoring the MMR effect. Subsequently, the influence of MMR on the velocity and microrotation fields as well as skin friction coefficient, is evaluated for various micropolar size and electric effect parameters and Hartmann numbers. It is concluded that depending on the parameters’ combination, as MMR varies, the fluid flow may accelerate, decelerate, or even excite a mixed pattern along the channel height. Thus, the MMR term is a side mechanism, other than the Lorentz force, that transfers or dissipates magnetic energy in the flow direct through microrotation. Acceleration or deceleration of the velocity from 4% to even up to 45% and almost 15% deviation of the skin friction were measured when MMR was considered. The crucial effect of the micromagnetorotation term, which is usually ignored, should be considered for the future design of industrial and bioengineering applications.

The Effectiveness of Mass Transfer in the MHD Upper-Convected Maxwell Fluid Flow on a Stretched Porous Sheet near Stagnation Point: A Numerical Investigation

“…Khan et al [20] recorded MHD nanofluid flow, along with non-linear radiation, through a non-linear stretching and shrinking wedge. A few relevant studies on MHD non-Newtonian fluids flow can be found in [21][22][23].…”

Effect of micromagnetorotation on magnetohydrodynamic Poiseuille micropolar flow: analytical solutions and stability analysis

“…Thus, represents a measure of the micropolar diffusion over molecular dissipation (Aslani et al. 2020).…”

“…1987 a , b ; Takashima 1996; Aslani et al. 2020). This approximation ignores the solution of the magnetic induction equation, which leads to a reduction of the equations to be solved.…”

“…Moreover, a constitutive equation for the magnetization is derived with the use of the dissipation function (Aslani et al. 2020). Then, the governing equations for the present MHD micropolar Poiseuille flow are (Shizawa & Tanahashi 1986): where B is the magnetic induction vector, is the density of the fluid, is the time, is the pressure, is the shear viscosity coefficient, is the vortex viscosity coefficient, is the current density, is the magnetization vector, l is the moment of inertia, is the angular viscosity coefficient, is the electrical conductivity, is the magnetic permeability, is the magnetization strength, is the identical tensor, is the Levi–Civita symbol, is the relaxation time of magnetization and is the magnitude of the magnetic field vector.…”

“…Recently, Aslani et al. (2020) studied a simple MHD micropolar Couette flow using this model, where they emphasized the effect of magnetization on the flow (micromagnetorotation – MMR effect). They concluded that when the MMR effect is considered, the MHD micropolar flow may accelerate or decelerate with differences from 4 % to 45 % compared with an MHD micropolar flow where magnetization is not included.…”