Fluid Friction and Leakage between a Stationary and Rotating Disc

This paper describes an investigation of the flow in a narrow gap between a rotating and stationary disc with an arbitrarily imposed radial pressure difference. This system represents the conditions pertaining between the rotors and casings of many fluid machines.The investigation is mainly experimental, for although the equations of motion were derived for the fluid system in question, these were found not to be tractable for the conditions observed. Experimental results are reported from two separate test series. The first test series yielded data on the frictional and pressure forces in the system which were obtained in sufficient detail for use in design calculations for fluid machinery. In the second series the flow between the discs was studied in detail in order to explain the nature and form of the results obtained in the first series of tests.