A computerized analysis is presented which may have the potential of calculating the performance of turbomachines operating in the stalled regime. The method however is still in its infancy in that here only radial impellers pumping incompressible fluids and working with the simplest of diffusers are considered.
The physical model consists of a rotating cascade which admits forward flows as well as backflows existing concurrently, both described as time steady jets and wakes flowing on two stream surfaces which must be in equilibrium. The losses for non-reattaching flows are mainly the result of momentum exchanges, making it possible to develop a model somewhat, but not entirely free of empirical quantities.
The sum of the physical constraints that must be satisfied form a system of nine simultaneous equations with nine variables. Their solutions are computerized for PC work. The output yields the internal pressures and velocity diagrams, including quantification of the forward and backward flows, suction line vortexing, cavitation and overall performance.
To the extent that it could be explored to date, corroboration against test pumps measurements shows promising agreement using as criteria the absorbed power and in a more preliminary way, the intensity of the suction pipe phenomena and the head-flow curves when appropriate. The corroborations however have been carried out only for a few pumps.