Investigation of the influence of test techniques,water speed and nuclei seeding on the characteristics of a high speed model propeller in a cavitation tunnel and correlation with full scale measurements 1

A high-speed model propeller of the Newton-Rader type has been tested in the Vosper Thornycroft Cavitation Tunnel in order to investigate influences affecting cavitation and performance data. Test velocity and cavitation nuclei content, dissolved gas and nuclei supply, have been varied; considerable influences on cavitation and thrust and torque coefficients were observed. Aspects of scale effects and techniques, effects of nuclei, Reynolds and Froude number as well as bubble dynamics are discussed. Additional experiments in simulated ‘behind’ ship conditions were carried out to correlate model with full scale trial results. Good agreement between model and prototype torque coefficients could be established for high ship speeds with test data obtained at high test velocities and relatively high gas content.