OSCILLATING-BLADED PROPELLERS 



S. Bindel ' ^- '^ 



Bassin d'Essais des Carenes 



Paris, France - '•-•■- 



SUMMARY 



Due to the inclination of shaft on the flow coming along the hull, the angle 

 of attack of the sections of a propeller blade is variable with the position of the 

 blade. The performances in cavitation are reduced especially for the sections 

 near the hub. 



In order to decrease these drawbacks, it is proposed to oscillate the blades 

 at the frequency of rotation of the shaft. 



The results obtained in cavitation for one propeller model do not seem as 

 promising as expected; however, further experiments are required in order to 

 form a valuable estimate of this type of propeller. 



SYMBOLS 



D Diameter of the propeller 



J = v/n D Advance ratio of the propeller 



n Number of revolutions of the propeller 



R Radius of the propeller 



r Radius of a blade element 



Tjj Radius of the hub 



X Reduced radius of a blade element 



Xh Reduced radius of the hub 



Ug, u^ Induced velocities 



V Velocity of the flow 



V^ Transverse component of the flow velocity 



W Amplitude of the transverse flow variations 



1497 



