Comparison of Theory and Experiment on Ducted Propellers 



C Power coefficient, -; '-..--. ; ...... 



2 



pn R^V^ 



J ■ ■■■ "" ■■ "■ 



C~ Thrust coefficient, -; 



\pnR'v^ -.:, ■,--,.. :.,.,.,,.:. 



D Propeller diameter 



Dj. Drag " '" 



h Chord-diameter ratio of duct '"' 



/ Propeller speed coefficient, v/nD ....•'. 



L Lift '■' ■' ■'■■•' 



M Moment 



n Propeller rps 



p Shaft power '' *■ 



p(x^, xp) Local pressure on duct 



Pq Free -stream static pressure 



R Propeller radius 



J?^ Duct radius 



T Thrust ' '"" • ^ '"''^ ' '■'' 



V Free -stream velocity 



w Axial induced velocity 



w Radial induced velocity 



X Nondimensional radius 



x^ Ratio of duct radius to the propeller radius 



a 



xp Axial distance from leading edge of duct nondimensionalized by the 

 duct chord 



Z Number of blades 



a Duct section angle of attack with reference to section nosetail line 



a Relative duct angle of incidence 



1341 



