Validation of a steady BEM-FEM coupled simulation with experiments on flexible small scale propellers

This paper presents numerical and experimental results for the validation of a coupled Boundary Element Method (BEM)-Finite Element Method (FEM) simulation for uniform flows. In the first part of the paper the numerical models and the BEM-FEM coupling are presented. A large part of the paper is dedicated to the validation procedure which has been successfully applied to three small scale flexible propellers. Special attention has been paid to improve the accuracy of blade deformation measurements in a cavitation tunnel test setup. Results of tests on a flat plate show that accurate deformation measurements can be performed with a stereo camera system in combination with a Digital Image Correlation (DIC) technique. In the last part of the paper blade deformations calculated with the BEM-FEM coupling are compared to experimental results. Depending on the flow condition a good agreement between measured and calculated blade deformations was obtained.Ship Hydromechanics and Structure