DYNAMICS AND KINEMATICS OF SUBALIRINE CABLE 



1179 



Cn = 



2wd cos a 1 



pi^ 



iV«2' 



(60) 



and with wd cos a a kno^^^l number, (60) and (58) can be solved for Co 

 and Nr as before. Thus, one can obtain Co from Figure 31 by merely 

 reading wd cos a rather than ivd on the abscissa. Knowing Co one can 

 solve for V from (56). 



3.0 



2.0 



1.5 



1.0 

 0.9 

 0.8 



'0-^ 2 4 6 8 10-6 



wd IN POUNDS ( ) 



10-5 



2 468"-' 2 466''-' 2 468 



10" 



,10- 



N. 



-^--:- 



^^^__^ 



^^^^^^ """^ "*~- 



la 



,-32 4 6 8,Q_2 2 4 6 8,^., 2 4 6 6, 2 4 6 8 ^^ 



wd IN POUNDS ( ) 



Fig. 31 — Variation of Co with wd for cables of smooth exterior. 



The results of such a computation are shown in Table II for cable 

 No. 1. For V > 1.5 knots the experimentally determined H is 64.0 de- 

 gree-knots. The corresponding computed values of H, ranging from 67.4 

 to 70.0 degree-knots, compare favorably with, this experimental value. 

 Over the entire range of V, from 0.25 to 10.00 knots, the variation in H 

 is about 4 per cent. This small variation makes the assumption of Section 

 3.2 that H is & constant for all T^ appear reasonable, especially since we 

 can only hope to use this computation in a preliminary design before 

 the hydrodynamic properties of a cable are established by experiment. 



Table II — Computed Values of Nr , 

 Cd , AND H for Cable No. 1 



