Oscillating -bladed Propellers 



Fig. 5b - Cavitation patterns for oscillating- 

 bladed propeller, > = ±3°, i/^ = 0, 6 = 10°, 

 J = 0.50, a = 5 



Fig. 5c - Cavitation patterns for oscillating - 

 bladed propeller, with oscillation in advance, 

 7 = ±3 , yp = 30°, = 10°, J = 0.50, a = 5 



fixed-bladed propeller, the inverted effect seemingly sensitive only for sheet- 

 vortex and tip- vortex cavitations. As already noted, according to (p there 

 exist two types of bubble cavitation in the upper part of the back. 



Inception of Cavitation — Figures 4b and 9b allow an evaluation of the influ- 

 ence of oscillation on the inception of the different types of cavitation. The 

 oscillation is beneficial as regards the bubble cavitation on the back near the 



1509 



