Our heavyweight helicopter equal in the world does not have
In Rostov started production of the most load-lifting rotary-wing car The Russian holding «Helicopt[...]
Moment Coefficient
Because the maximum camber ratio of a thin airfoil is small by definition, the moment expression for a cambered airfoil can be represented adequately by the expression derived for a symmetrical airfoil (i. e., flat plate). Then, referring to Fig. 5.21 and the development for a symmetrical airfoil:
c c
MLle = – J(PL – PU)(x)dx = – J(pVji)(x)dx.
0 0
 |
![Подпись: Jy (Ф)[1 - cos Ф]^ІП ф)dф. 0](/img/3130/image573.gif "Moment Coefficient"){kind=small} |
Applying the transformation from linear to angular measure and writing this equation in coefficient form results in:
 |
 |
 |
Substituting for у (ф) = у (0) from Eq. 5.21 and integrating using basic trigonometric identities and integral tables results in:
The moment coefficient for a cambered airfoil is seen as depending on only three Fourier-series coefficients and as a function of the angle of attack and camber.
