Resonant oscillations of a porous plate in an electrically conducting rotating viscous fluid

Abstract

An unsteady analysis is made of the nontorsionally generated hydromagnetic flow in a semiinfinite expanse of an electrically conducting rotating viscous fluid bounded by an infinite nonconducting porous plate with uniform suction or blowing in the presence of a transverse uniform magnetic field. The structure of the steady and the unsteady velocity distributions and the associated hydromagnetic multiple boundary layers are investigated including the case of blowing and resonant oscillations. Both the steady and the unsteady velocity fields describe the general features of the hydromagnetic boundary layer flows in the rotating fluid including the effects of uniform suction or blowing for all frequencies of oscillations of the plate. Unlike the hydrodynamic situation for the case of blowing and resonance, the hydromagnetic steady-state solution satisfies the boundary condition at infinity and the associated boundary layers are confined to the plate. The inherent difficulty involved in the purely hydrodynamic problem associated with the case of blowing and the resonant frequency has been resolved in this paper by the addition of the magnetic field.