Dynamias of Submerged Towed Cylinders 



that oscillatory instability occurs for A > 0.20, Once again agree- 

 ment in behavior of the rigid body and the flexible body (for u = l/V2) 

 is good. Similar calculatio'is confirmed agreement with the other 

 stability maps of [ 26] . 



Two stability diagrams were constructed (Figs. 14 and 15) 

 showing the effect of €C|^, ecj, f2 and A on stability, for comparison 

 with those to be obtained using the new theory. 



YAWING 



Fig. 14, The effect of €c^, €Cj and fg on stability of a 

 rigid cylinder with A= i,f, = 1-C|=i, 



C2= l-f2 and Xi = Xz = 0.01. ^^t ~ ^'^'' 



ecT=0,5; ec^=l. (Theory of [26] ). 



In Fig. 14 we observe that unless ec^ is considerably less 

 than ecfj, the region of oscillations practically covers the whole 

 plane; moreover, oscillations persist to lower values of f- than 

 yawing does . 



In Fig, 15 we see that a sufficiently short tow-rope has a very 

 definite stabilizing effect on the system, as far as oscillatory insta- 

 bility is concerned. Very long tow-ropes, on the other hand, evi- 

 dently have a very weak stabilizing effect. 



The foregoing clearly establish that the dynamical behavior 

 of the rigid body is represented by the behavior of the zeroth and 

 first modes of the flexible body at small u. 



One noteworthy aspect of the analysis is that the existence of 

 yawing instability cannot be affected by varying A, i.e. by altering 



1007 



