Time‐dependent MHD Couette flow in a rotating system with suction/injection

Abstract

AbstractThe unsteady MHD Couette flow of a viscous incompressible electrically conducting fluid between two parallel porous plates in a rotating system when one of the plate is set into uniform accelerated motion is studied. A unified closed form analytical expressions for the velocity and the skin friction for the magnetic lines of force being fixed relative to either the fluid or the moving porous plate are derived using the Laplace transform technique. The effects of suction/injection parameter in the presence of magnetic field and rotation on both the primary and secondary velocities and the resultant skin friction are presented graphically. The analysis of the result shows that the primary velocity increases with increase in the suction/injection parameter while the secondary velocity increases in magnitude near the moving plate and decreases in magnitude near the fixed plate for the two cases. It is interesting to note that the Ekman number has an increasing effect on the primary velocity when the magnetic lines of force are fixed relative to the moving plate. On the other hand, the resultant skin friction decreases with increase in the suction/injection parameter at the porous plate where injection takes place and increases at the porous plate where the fluid is been sucked for the two cases considered.