Similarity solutions for the squeezed film flow between two rotating naturally permeable discs

A Newtonian fluid film squeezed between two rotating discs which are made up of naturally permeable (porous) materials and of finite thickness has been considered. Similarity solution has been obtained when the discs at time t are separated by a distance H(1 - alpha t)(1/2), rotating with angular velocities proportional to Omega(i)(1 - alpha t)(-1) and of permeabilities k(i)(1 - alpha t) (i = 1,2 for lower, upper disc) where H, alpha(-1), Omega(i) and k(i) denote a reprsentative length, time, angular velocities, and permeabilities of the discs, respectively. The effects of rotation and permeabilities have been studied on velocity profiles, the load capacity, and the torques which the fluid exerts on the discs. If we take the discs of same permeability, there exists a critical value of permeability above and below which the behaviour of various physical quantities changes.