Numerical simulation of the cavitating KP505 propeller working in open water conditions

Abstract

The present paper proposes a numerical study, fully experimentally validated, usable for the optimal design of the naval propulsion features. The marine propeller KP 505 is a representative propeller geometry with experimental available detailed, so this is chosen as a reference for probing the accuracy of the present study. Data obtained from this model is extensively used to provide validation for unsteady RANS calculations, with specific interest in predicting tip-vortex flow characteristics. The method used is based on the fundamental conservation equations. Since DNS modeling requires excessive computational effort due to the very dense discretization of computational domain and very limited time step, it is assumed that the influence of turbulence on the flow is derived with sufficient accuracy based on the averaged flow parameters. In the present computations the EASM model is applied, which proved to be a stable and accurate model. The computed overall accuracy of the proposed model is validated by an extensive comparison with experimental data from the free running tests performed by NMRI Tokyo and HSVA Hamburg. The main features of the flow field, with particular attention to the vortical structures detached from the blades are comparatively presented in an attempt to validate the technique proposed.