Dynamics of Hydrofoils as Applied to Naval Propellers 



of the lift coefficient by incidence, as is shown in Fig. 10, which refers to a pro- 

 file NASA 16, a = l, tjc= 0.06, c^ = 0.314, c^^ = 0.9 c^, c^^ = 0.1 c^. 



o,i 



0,1 0.3 



0,4 as 0,% 

 %chord 



a 7 0,5 



0,9 



i.O 



Fig. 10 - Depression distribution on the suction side of a section foil NASA 

 16 a = 1, t /c = 0.06, c, = 0.314, c,= 0.1 c^ , c = 0.9 c . 



2.4 Performance in Actual Flow 



In actual flow the hydrodynamic characteristics of hydrofoils change quite 

 considerably. The experimental data available are rather scarce, doubtful, and 

 poorly correlated. As far as the foils considered in the present study are con- 

 cerned, these data refer only to experiments in air at a Reynold's number (re- 

 ferring to the chord) between 3 and 9 x 10 6, and with thickness ratio t^/c > 0.06, 

 notably larger than the smallest ones used in the design of naval propellers (and 

 which are usually of more interest with regard to cavitation effects). 



For this reason, systematic, experimental research in water would be very 

 welcome. Such research should include the two thickness forms NASA 16 and 

 66 mod, the three mean lines a = l, a = 0.8, and NASA 65, and should cover a 

 range of thickness ratios from 0.03 to 0.2, while the angle of attack should vary 

 between 0° and 5°. 



In the following paragraphs several average values are reported as they re- 

 sulted out of an examination and interpretation of the experimental data of NASA 

 Report 824. For want of something more precise, these data may be employed 

 in naval propeller design. 



1033 



