The Geometry relation 0=B Bt 6=B6 6=B6 1=元 1=元 Ab= BA A0=B4 tan xo=o tan x tan no =o tan x
The Geometry relation: tan 1 tan 0 0 0 0 0 0 = = = = = = A A tan 1 tan 0 0 0 0 0 0 = = = = = = A A
The relation of Aerodynamic coefficients 210C 2210p Ba B25 P B 2p,0 C(M,t, 0,a, A, tan x,n)= PC,(M=0, Br,BB, Ba, BA,otan x, a) This correction rule is Goethert Rule
The relation of Aerodynamic coefficients: 2 ,0 2 1 2 1 ˆ 2 p x p C V V C = = − = − tan , ) 1 ( 0, , , , , 1 ( , , , , ,tan , ) 2 C M A C M A p p = = 2 ,0 2 1 2 1 ˆ 2 p x p C V V C = = − = − This correction rule is Goethert Rule
Derivation of the 3-D Prandtl-Glauert correction rule from Goethert rule C(M,t, 0,a, A, tan x, n) C (M=0, T, 0, a, BA,tan x, n B Cn(M=0, Br, BB, Ba, BA,tan x, n) C(M=0,T, 6,a, BA,tan x, n
tan , 1 ( 0, , , , , tan , ) 1 ( 0, , , , , 1 tan , 1 ( 0, , , , , ( , , , , ,tan , ) 2 C M A C M A C M A C M A p p p p = = = = Derivation of the 3-D Prandtl-Glauert correction rule from Goethert rule:
Cn(M, T, 0,a, A, tan x, n) C(M=0, t, 0, a, BA,tan x, n) B This is the Prandt -Glauert correction rule
tan , ) 1 ( 0, , , , , 1 ( , , , , ,tan , ) C M A C M A p p = = This is the Prandtl-Glauert correction Rule
Nonetheless, changing the lift curve slope just by the Prandtl-Glauert factor does not do too badl 2几凸 阝(A+2 A somewhat better approximation is obtained by applying the Prandtl-Glauert correction to the 2-D lift curve slope, then applying the downwash correction from lift line theory 2n(-e)2t 2亿凸 A+2
Nonetheless, changing the lift curve slope just by the Prandtl-Glauert factor does not do too badly: A somewhat better approximation is obtained by applying the Prandtl-Glauert correction to the 2-D lift curve slope, then applying the downwash correction from lift line theory