This paper studies the effects of injection/suction on oscillatory flow of a viscous incompressible fluid through a porous medium in a porous channel. The porous channel with constant injection/suction, rotates about an axis perpendicular to the plates of the channel. A magnetic field of uniform strength is also applied perpendicular to the plates. The upper plate is allowed to oscillate in its own plane with the velocity U*(t*), while the lower plate is at rest. The effects of Coriolis force, the magnetic field and porosity of medium on the flow are studied. The resultant velocities R₀ and R₁ for the steady and unsteady parts respectively along with their phase angles and have been discussed in detail.

Magnetofluiddynamics (MFD) or Magnetohydrodynamics (MHD) has gained considerable importance because of its wide ranging applications in physics and engineering. In astrophysics and geophysics, it is applied to study the stellar and solar structures, interplanetary and interstellar matter, solar storms and flares, radio propagation through the ionosphere, etc. In engineering, it finds its application in MHD generators, ion propulsion, MHD bearings, MHD pumps, MHD boundary layer control of re-entry vehicles, etc. MHD has attracted the attention of a large number of scholars due to its diverse applications. Attia and Kotb (1996) studied the MHD flow between two parallel porous plates. Yen and Chang (1964) analyzed the effects of wall electrical conductance on the magnetohydrodynamic Couette flow. MHD flow in a duct has been studied by Chang and Lundgren (1961). In the recent years, a number of studies have appeared in the literature on the fluid phenomena on earth involving rotation to a greater or lesser extent (Vidyanidhu and Nigam, 1967; Gupta, 1972a; and Jana and Datta, 1977). Injection/suction effects have also been studied extensively for horizontal porous plate in rotating frame of references by Gupta (1972b), Mazumder et al. (1976), and Soundalgekar and Pop (1973) for different physical situations. The fluid flows in rotating channels have been studied by a number of scholars, viz., Mazumder (1991), Ganapathy (1994), and Singh (2000); and Singh et al. (2005) have obtained an exact periodic solution of oscillatory Ekman boundary layer flow through a porous medium bounded by two horizontal flat plates. Singh and Mathew (2008) studied injection/suction effects on an oscillatory hydromagnetic flow in a rotating horizontal porous channel. This paper studies the effects of injection/suction on an oscillatory hydromagnetic flow through porous medium in a rotating porous channel.

We consider the oscillatory flow of a viscous, incompressible and electrically conducting fluid through a high porous medium bounded between two insulating infinite parallel porous plates, distance d apart. A magnetic field of uniform strength B₀ is also applied perpendicular to the lower horizontal plates. A constant injection velocity w₀, is applied at the lower stationary plate and the same constant suction velocity w₀, is applied at the upper plate which is oscillating in its own plane with a velocity U^*(t^*) about a non-zero constant mean velocity U₀.

Computational Mathematics Journal, Oscillatory Hydromagnetic Flow, Magnetofluiddynamics, Magnetohydrodynamics, Solar Structures, Rotating Channels, Constant Injection Velocity, Velocity Components, Magnetic Field Parameters, Injection Parameter, Porous Channel.