Fluid Flow Equations for Rotordynamic Flows in Seals and Leakage Paths

Abstract

Fluid-induced rotordynamic forces produced by the fluid in an annular seal or in the leakage passage surrounding the shroud of a pump or turbine, are known to contribute substantially to the potential excitation forces acting on the rotor. In this paper we explore some of the important features of the equations governing bulk-flow models of these flows. This in turn suggests methods which might be used to solve these bulk-flow equations in circumstances where the linearized solutions (such as those of Childs 1987, 1989) will no longer be accurate. An example of a numerical solution is then presented.