Flow in a Narrow Gap along an Enclosed Rotating Disk with Through-Flow

Flow in a narrow gap along an enclosed rotating disk with superimposed through-flow is studied theoretically and experimentally. When the axial gap is narrow, or when a large radial outflow is superimposed, the boundary layers on the rotating and stationary walls interfere with each other. The present study proposes an analytical model for such an interfered gap flow and give a theoretical analysis which is easily applicable to various boundary conditions. For a non-interfered gap flow, the theoretical analysis giving better results than the conventional one is also presented and the critical gap between these two flow patterns is determined theoretically. It is revealed that the radial pressure distribution is dependent mainly on a wall shearing stress and radial expansion of a sectional area in the interfered gap case and on a centrifugal force of the core region in the non-interfered gap case. The coefficient of disk friction moment is shown to be proportional to Re^<-1/4> in the interfered gap case and Re^<-1/5> in the non-interfered gap case