Forces caused by the radial out-flow between parallel disks

An experimental program, to determine the magnitude of the force on the impact disk for the radial out-flow between parallel disks, has been carried out for moderate Reynolds numbers. The present results are compared with a previously published, ad hoc, analytical formulation whose coefficients were established for low Reynolds numbers. Acceptable agreement exists for the low Reynolds number range of the present study; progressively significant disagreement is observed as the Reynolds number is increased. The present force data, when combined with previous observations and interpreted via appropriate theoretical considerations, reveal a complex blending of flow phenomena for the Reynolds number, diameter ratio, and plate separation values of the present study.