Response of Propulsors to Turbulence 



2.0 



Fig. Z - Correlation curve for isotropic turbulence. 

 The measurements were made at 30M downstream, 

 where M is the naesh size of the grid producing the 

 turbulence 



the span of a blade and denoted by the subscript T. A good choice would be the 

 section exerting the largest steady lift force. 



3. The velocity correlation tensor is approximately represented by 



Rw^r(-) -- -"^'^ Rkk(-) ■ 



where q represents the distance between the elements k and r of the propeller. 

 As a consequence we obtain the following components: 



R^i(T) = u^ e ^ , 



^i,'(^> = -^1' - 1 "t?^ """'"""' 



Rkr(^) = Kkr(^) = ■ 



We can now obtain an expression for the mean square thrust coefficient. 

 Consider the geometry of a propeller element, as shown in Fig. 3. We approxi- 

 mate the angle fi by 



tan /3 



n-R 



297 



