Page 209 - Fluid-Structure Interactions Slender Structure and Axial Flow (Volume 1)

PIPES CONVEYING FLUID: LINEAR DYNAMICS I 191

I 1 I I I 1 I
1
I I
22

‘N=7 J
18 /N=6

If
13

10

6
0 20 30 60 80 100
Y
Figure 3.80 The values of u where the locus of one of the modes of the articulated system crosses
the origin for N = 2-8 and e = as a function of y; the meaning of the dashed lines is explained
in the text (Pafdoussis & Deksnis 1970).

Table 3.7 Conditions of stability: theory compared with experi-
ments; in (a) k varied from one experiment to the next, in the range of
k = 0.33-0.39Nm, while in (b) k 2 0 (Pai’doussis & Deksnis 1970).
(a) Flutter

2 1 0.23 1 4.94 4.20 4.25
2 7 I - 0.227 17.2 6.36 5.76
2 I - 0.084 46.4 6.08 6.17
2
3 ; 0.211 18.6 6.20 6.12
4 f 0.196 20.2 6.65 6.44
(b) Divergence

2 I 0.258 1.39 1 .so
2
2 I 0.258 1.40 1.34