18.08.2013 Views

Download - NASA

Download - NASA

Download - NASA

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

_" 6-t_<br />

0<br />

"_ s--<br />

"0<br />

r-<br />

0_<br />

Q.<br />

><br />

4<br />

==3<br />

_f<br />

_,2<br />

t_<br />

¢-<br />

t_<br />

_E 1<br />

t_<br />

0<br />

"o<br />

"o e-<br />

¢u<br />

en<br />

X<br />

GI,<br />

v<br />

><br />

==<br />

E<br />

tf<br />

¢X<br />

E"<br />

r-<br />

00<br />

E<br />

0<br />

-1<br />

-3<br />

(a)<br />

0, ....... O<br />

k<br />

I<br />

Airspeed,<br />

KTAS<br />

o 250<br />

[] 275<br />

A 300<br />

o 325<br />

v 350<br />

÷ 375<br />

I<br />

x 400<br />

13o/ _E / _S<br />

.,ff.x<br />

0 o / _0 / _E / _/Sj=I_I<br />

-2.5 -2<br />

M<br />

-1.5 -1<br />

I--e _3+1<br />

(b)<br />

-1<br />

-1.4 -1.2 -1 .8 -.6 .4 .2 0 ,2<br />

Oo<br />

01 I___,._ _ __'B'O _3 - 1<br />

132 1 _E<br />

Real part, per rev (expanded scale)<br />

01-1 ,lrll<br />

133 / 130 / _1<br />

01+1 ¥_--------_<br />

_ m A A m<br />

m<br />

_ 0 0<br />

_---__<br />

_2<br />

.___l_ _131 +<br />

lID [3G IR<br />

_0 1_E<br />

'---@'IIaI_,IB_ )-------I_IIi<br />

x<br />

134 - 1<br />

_3+1<br />

o _3-1<br />

Real part, per rev (expanded scale)<br />

13c<br />

-.5<br />

|<br />

J 0<br />

I<br />

Airspeed,<br />

KTAS<br />

o 250<br />

[3 275<br />

& 300<br />

o 325<br />

v 350<br />

+ 375<br />

I<br />

) 400<br />

Oo/ 130/ _l<br />

(;h<br />

K.I,'qP<br />

n<br />

dl<br />

qB _m_<br />

0 --w<br />

Figure 6. Eigenvalues for CO7 model with additional flutter-solution degrees of freedom; 250-400 KTAS speed variation<br />

at 86% rotor speed. (a) Symmetric modes. (b) Antisymmetric modes.<br />

'1<br />

45

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!