An insight on the propeller signature by optical techniques

The problem of the propeller wake signature is tacked in the present paper through the analysis of three configurations of relevance: the perturbation of an isolated propeller, the problem of a propeller operating in behind condition and the propeller-rudder interaction. The results presented in the paper are part of a research program on marine propulsion of the Italian Ship Model Basin (INSEAN). In this framework INSEAN has been developing and implementing a number of measurement tools, pioneering sometimes, to address the complex problem of the experimental analysis of marine propellers. Laser Doppler Velocimetry, Particle Image Velocimetry (2D-2C PIV, Stereo-PIV, Defocusing PIV, high- speed PIV), imaging techniques for the cavitation pattern measurement are among the most successful techniques and have provided new insights for a better understanding of the complex flow patterns in a propeller wake.