MHD flow over a moving plate in a rotating fluid with magnetic field, Hall currents and free stream velocity

Mixed convection hydromagnetic flow in a rotating channel with Hall and wall conductance effects

A study is made of the unsteady flow engendered in a second-order incompressible, rotating fluid by an infinite porous plate exhibiting non-torsional oscillation of a given frequency. The porous character of the plate and the non-Newtonian effect of the fluid increase the order of the partial differential equation (it increases up to third order). The solution of the initial value problem is obtained by the method of Laplace transform. The effect of material parameters on the flow is given explicitly and several limiting cases are deduced. It is found that a non-Newtonian effect is present in the velocity field for both the unsteady and steady-state cases. Once again for a second-order fluid, it is also found that except for the resonant case the asymptotic steady solution exists for blowing. Furthermore, the structure of the associated boundary layers is determined.

Rotating flow of a second-order fluid on a porous plate

Closed-form solutions are presented for the transient hydromagnetic flow in a rotating channel with inclined applied magnetic field under the influence of a forced oscillation. Magnetic Reynolds number is large enough to permit the inclusion of magnetic induction effects. The Maxwell displacement current effect is also included and simulated via a dielectric strength parameter. The governing momentum and magnetic induction conservation equations are normalized with appropriate transformations and the resulting quartet of partial differential equations are solved exactly. A parametric study is performed of the influence of oscillation frequency parameter (ω), time (T), inverse Ekman number, i.e. rotation parameter (K2), square of the Hartmann magnetohydrodynamic (MHD) parameter (M2), and magnetic field inclination (θ) on the primary and secondary induced magnetic field components (bx, by) and velocity components (u, v) across the channel. Network solutions are also obtained to validate the exact solutions and shown to be in excellent agreement. Applications of the study arise in planetary plasma physics and rotating MHD induction power generators and also astronautical flows.

Transient hydromagnetic flow in a rotating channel permeated by an inclined magnetic field with magnetic induction and Maxwell displacement current effects

In the present study, an analysis for steady hydromagnetic mixed convective generalised Couette flow between two infinite parallel plates of arbitrary electrical conductivities and finite thicknesses filled with a porous medium in the presence of a uniform transverse magnetic field in a rotating system with the Hall effect is presented. The heat transfer characteristics of the fluid flows are also investigated, taking viscous and Joule dissipations into account. Exact solutions of the resulting simultaneous ordinary differential equations governing the fluid flows are obtained in a closed form. The closed form analytical solutions for shear stress and mass flow rate are also obtained. To examine the physical consequences and flow characteristics, the numerical results for velocity, induced magnetic field, temperature field, shear stress, mass flow rate, and rate of heat transfer are computed for different values of various system parameters and are displayed in graphical and tabular forms. An interesting observation recorded that there arises flow reversal in the secondary flow direction when the permeability parameter is very small, i.e., when Darcian drag force is very large.

Influence of Hall current and wall conductivity on hydromagnetic mixed convective flow in a rotating Darcian channel

The paper studies the combined free and forced convection in a rotating, viscous, incompressible fluid confined between two parallel porous plates. Assuming that the temperature varies linearly along the plates and the pressure gradient maintained uniform over the planes parallel to the plates, the velocity, temperature and the stresses are calculated analytically. Their behaviours for different values of the parameters viz., the Hartmann number, the Grashoff number and the suction parameter etc., are discussed graphically giving out the interplay between the various forces.

D. V. Krishna

Papers

Transient hydromagnetic convective flow in a rotating channel with porous boundaries

Mixed thermal convection in a cylinder of non-uniform gap