T. Linga Raju and V. Gowri Sankara Rao
The theoretical problem of an unsteady viscous flow of an ionized gas with constant properties in the presence of an applied magnetic and electric field through a horizontal channel bounded by two parallel porous plates, subject to an uniform suction, applied normal to the plates, by taking Hall currents in to account is investigated. The transpiration velocity distributions are assumed to vary periodically with time about a non-zero velocity. The closed-form solutions for the velocity distributions, such as primary and secondary velocity distributions, also the corresponding mean velocities are reported for small periodic frequency parameter when both plates are made up of non-conducting and conducting porous materials. These results are depicted graphically to elucidate the interesting features of the flow pattern in presence of Hall currents. We note that, when the motion is in steady state and for non-porous plates, these results coincide with those of Sato [20]. Also, it is noticed that, the velocity distributions thus obtained are found to be the independent of s ( the ratio of electron pressure to the total pressure ) in case of non-conducting porous plates and are depending on ‘s’ for the case of conducting plates
