A General Computational Technique for the Prediction of Cavitation on Two-Stage Propulsors

An iterative technique for the prediction of the performance of two-component propulsors, includ­ing the effects of sheet cavitation, is presented. A vortex-lattice method, originally developed for the prediction of the performance of cavitating single propellers in non-axisymmetric inflow, is applied to each one of the components. The "effective" wake for each component is determined via an Euler solver, based on a finite volume method, in which both components· are represented via body forces. The axisymmetric version of the method is used to predict the mean performance of a contra-rotating propulsor and of a pre-swirl stator/rotor combination. The non-axisymmetric version of the method is used to predict the non-axisymmetric flow-field in the wake of a pre-swirl stator, and the unsteady cavitating flow performance of the rotor subject to that flow-field.