force coefficients such as those reported by Sarpkaya (12) and Griffin and Koopmann (4) are used to 

 predict the resonant crossflow oscillations. A discrete vortex model for predicting the vortex-excited 

 oscillations of a flexibly-mounted rigid cylinder has been developed by Sarpkaya and Shoaff (66). A 

 numerical integration of the time-dependent Navier-Stokes equations in the presence of an oscillating 

 cylinder has been reported by Hurlbut, Spaulding and White (67). However this numerical scheme is 

 limited to low Reynolds numbers, i.e. Re < 200. These four classes of predictive models are discussed 

 in Appendix E. 



4.2 General Design Procedures. Design procedures and prediction methods for the vortex-excited 

 oscillations of structures and cable systems have been developed only recently. Previously a reliable 

 experimental data base and accurate characterization of the phenomenon were relatively unavailable, 

 and it is only since marine construction has moved into deeper water (and more harsh operating 

 environments) and since the requirements of oceanographers and acousticians have become more 

 sophisticated that the need for sophisticated design procedures has arisen. The need to design slender, 

 flexible structures against problems due to vortex shedding in the atmospheric environment also has 

 spurred renewed efforts to develop new wind engineering design procedures. It should be emphasized, 

 however, that reliable data are now available only at subcritical Reynolds numbers. 



The design procedures that are available have been reported by Hallam, Heaf and Wootton (68), 

 King (2), and Skop, Griffin and Ramberg (59,69). These various approaches have been unified on a 

 common basis by Griffin (3). The following discussion is structured similarly to those of Hallam at al. 

 and King, whose primary applications thus far have been to the design of marine structures. The 

 methods developed by Skop, Griffin, and Ramberg have been applied primarily to the analysis of 

 marine cable systems, though many of their basic findings have been incorporated by others in the 

 marine industry (70). Blevins (71) discusses design problems due to flow-induced vibrations in gen- 

 eral, including heat exchangers, overhead transmission lines and marine structures and cables. 



A general flowchart which lays out a calculation procedure for assessing the response of a struc- 

 ture or cable due to vortex shedding is given in Fig. 4.1. Both single members and arrays of members 



