Lehman and Kaplan 



2.00 r 



1.00 



0.80 

 0.60 



0.40 



■P 

 in 



3 

 U 



u 0.20 



(U 



rH 



■H 

 (U 



a 

 o 



"qT 0.10 

 o 



P 0.08 



0.06 



0.04 



0.02 



0.01 



0.25 0.50 



Spacing/Propeller Difutieter 



Fig. 17 - Effects of propeller blade thickness and 

 appendage asymmetry on transverse measure- 

 ments with a three -bladed propeller 



the induced force which is independent of the propeller thrust coefficient, but the 

 percentage of the induced force attributed solely to the thickness term becomes 

 larger as the absolute thrust of the propeller decreases. In other words, at a 

 condition of zero propeller thrust there would still be a force induced on the ap- 

 pendage due to the thickness of the passing propeller blade. 



The technique proposed here of presenting the induced appendage force as a 

 ratio solely dependent on propeller thrust is thus recognized as not representa- 

 tive of a true scaling parameter, as the thickness contribution is lumped to- 

 gether with the loading contribution. However it does seem that the ratio 



188 



