Design and Evaluation of a Highly Skewed Propeller.

摘要

The report discusses the design process and evaluation of a highly skewed propeller installed on the American Export Lines,Inc. 78a Class Roll-On/Roll-Off Cargo Vessel. The design process is discussed in detail including consideration of propeller excited vibratory forces,cavitation,and time average and fluctuating stresses. Experimental results of the first skewed propeller design are presented which indicate that the propulsion and cavitation performance was satisfactory,however,the rpm was 3.7percent below that which could be used with the existing shafting and gears. A second design and model evaluation was undertaken. The results presented in the report show that this propeller propulsion performance is comparable to the conventional propeller. Experimental procedures and results from the study on the erosive impact intensity of cavitation for the model propeller and the ship's propeller are presented. Hull vibration measurements for the vessel fitted with conventional propeller and skewed propeller are compared. Vibration levels have been considerably reduced using the skewed propeller while maintaining equivalent performance.