Dynamias of Submerged Towed Cylinders 



Im(w) 



Re(w) 



Fig, 13 The dimenslonless complex frequencies of the second and 

 third modes of a flexible cylinder with f, = 0.7, c, = 0, 

 f2= 1 - C2= 0.7, A = 1, X, = X2 = 0»0i; ec^ = €c^ = 1; 



ec^= ec^ = 0.5. 



(New theory) 



We next consider quantitative agreement for one specific 

 case, the details of which are given In [ 26] : a cylinder with quite 

 well streamlined nose and tall, e = 20.4 and A = 1 (cf. Table 2 

 of [ 26]). Theory Is compared with experiment In Table 1. The 

 rationale for the choice of parameters used to obtain the theoretical 

 values has been discussed In [ 26] and will not be unduly elaborated 

 here. The parameters used are ec,^ = ecj = 1 , A = 1 , f , = 0, 8, 



= 0, 



f2= 1 - 



= 0.7, X, = 



the tail Is quite well streamlined, f2< 1 and C2 ^ were taken 



= X2~0,01, It Is noted that, although 



2 

 (cf. [ 26] ), as the tall cannot be considered to be perfect In the sense 

 described In §3, I.e. with regard to two-dlmenslonallty of the lateral 

 flow and lack of separation In the axial flow. On the other hand, the 

 nose, although of Identical shape to the tall, must have a value of f| 

 nearer unity, as no separation takes place over the nose. Accordingly, 

 f , = 0.8 and c, = were taken In the new theory; (the calculated 

 values of the old theory, also given in Table 1, were obtained with 

 f, = 1, which Is considered to be unrealistic, as the lateral flow over 

 the nose Is no nmore truly two-dimensional than over the tall). 



1001 



