Ducted and Contrarotating Propellers on Merchant Ships 



Fig. 4 - Family of contra- 

 rotating propellers. Blade 

 form. Figures give 1/D. 



X = 0.95 

 0.9 



OB 



0.7 



0.6 



05 



0.4 



0.3 

 0.2 



1.4 



PID 



1.2 _ 



1.0 _ 



0.6 



0.6 



04 _ 



0.2 



03 



0.4 



Q5 



0£ 



0.7 



0.6 



0.9 



■.rlR 



1.0 



Fig. 5 - Family of contrarotating propellers. Radial distributions 

 of pitch. See further Table 1 (D = forward and aft propeller diam- 

 eter, respectively). 



1273 



