Sohreibev 3 Bentkowsky and Kerr 





z 



UJ 



O 

 U 



5 



O 



5 



FORWARD SPEED/IMPELLER SPEED ^ (FT ./SEC ./k PS) 



Fig. 9. Effect of Forward Speed on Duct Movements 



When the propeller in the duct is accelerating, the thrust 

 component due to the propeller is a function of the ratio of jet 

 velocity, Vj , to propeller speed, n. The thrust coefficient for a 

 propeller of this type was estimated from data taken from Ref. 10 

 and fit with a second order curve resulting in 



Tpmn= iO.63 n^nlnmn 



c; 04. V Iv- I • -LlTOD. > 

 - D.U4 vjnini Vjmnl » ^T — " 



= 10.63 n^Jn^J + 6.0 n„ J Vj^J - 5.04 Vj^nlVj^nh 



Qmn < 

 mn 



1144 



