International Conference on Propeller Cavitation, May 16-18, 1995, University of Newcastle upon Tyne
cavitation; propeller; ice
Ships which operate in arctic and sub-Arctic conditions are often subjected to momentary increased propeller cavitation because ice pieces block the flow into the propeller. Model tests have shown that such ice blockages lead to regions of violent cloud cavitation. There is a possibility that severe erosion occurs on full scale propellers while operating in these conditions. Erosion tests, using paint films, were carried out in the cavitation tunnel at the Institute for Marine Dynamics (IMD) with a 200 mm diameter model propeller of the type which is fitted to the Canadian R-Class ice-breakers. A simulated ice blockage was installed in the tunnel ahead of the propeller and tests were conducted over a range of cavitation numbers and advance coeffieients. The types of cavitation which occurred as a result of the blockage were documented. The areas of erosion were estimated and the erosion patterns were photographed for each test condition.