EARLY DESIGN-STAGE APPROACH TO REDUCING HULL SURFACE FORCES DUE TO PROPELLER CAVITATION

The approach for the selection of parameters at a very early design stage to reduce hull surface excitation forces induced by blade cavitation has been based on regression anlaysis of data from model wake field measurements and full-scale investigations. Recommendations on the selection of after-body lines to reduce the "wake peak" are given for both slender V-shaped and full-form ships. Criteria for acceptable pressure fluctuations on the hull are presented which should give satisfactory local vibration levels in the afterbody structure as well as global vibration levels in the accommodation area. Further, more specific guidelines are presented on how to select main propeller parameters and clearances to give the best basis for future investigations. How to use the developed methods in a complete design procedure is proposed.