Brard 



4 r r* H 



Z] ^kA fok(0+) ^A(t') + J 577 fokC-^') <^kA(t'-r')dr' 



4 t' 



= E ^UaJ fok(^') 0kA(t'-r')dr' , 



and the effective angle is a^ = a^- Aa^, with 

 4 [- t ' 



A'-e = - E ^kA fokCt') - [ fok(^') <^A(t'-T')dr' 

 k = 3 L "^0 



One has 



0kACO) = , 0kA(+°°) = 1 ; 



4>]^fi^(t') is monotonic. 



The set of hydrodjniamic forces due to the rudder (and aileron) is: 



^A = - 2^^aU'c^^ 



1 Tl2 



Ya = - o/'o-aU'c 



'''{^],.'nTl.^A 



i^Mu),, ^n^j,,^Aj 



[1+...] , 



^ + Cf03 + f04^A - foS^A) - E ^kA fok - ^'^e 



Za = 0. 



£a = ^P-aLU^c C, 



1^2 (g)^, + 2 





^ + (f03 + f04^A - foS^A) - E ^kA fok - ^'^e 





^ + (f03 + fo4^A - fos^A) - E ^ka fok " ^^e 



876 



