S' 



Oscillating-bladed Propellers 



X =0.20 

 H 



• = 15° 



. 4 



.6 



1.0 



Fig. Zb - Variation of incidence on the blade 

 element due to shaft inclination, xj^ = 0.20 

 and (9=15° (supposing Ug = "t ~ ^) 



It must be noted that the calculations made above do not take into account 

 the length of the sections. In fact, if this length is not small relative to the 

 "wavelength" 277r, a sophisticated theoretical approach can take into account 

 not only the mean incidence at each position of the blade but also the camber of 

 the relative flow. In addition, the variations of the induced velocities u^ and 

 Uj are probably not negligible. 



1501 



