Kim and Mevciev 



SLENDER VERTICAL FLOATS ISOLATED PERFOR- 

 MANCE AND INTERACTION EFFECTS FOR LARGE 

 ARRAYS 



Relatively simple analytical procedures provide sa - 

 tisfactory description of the heave response of slender 

 vertical floats to waves. It is found that viscous ef- 

 fects must account for most of the heave damping for 

 such slender floats and that it is advisable to introduce 

 specially-engineered damping devices to control re- 

 sonant heaving motions . 



Force and motion studies of a large array (210 ele- 

 ments) of slender floats reveal important interaction 

 effects on wave-induced forces and, especially, heave 

 motions. A satisfactory theoretical explanation of 

 these effects is not yet available but a continuing em- 

 pirical investigation is planned. 



INTRODUCTION 



This paper presents results for a somewhat "mixed-bag" of 

 studies of the hydrodynamic performance of floating platforms in 

 waves. The nature of these investigations range from systematic ex- 

 perimental determinations of the performance of multiple float sup- 

 ported platforms in irregular seas to rather sophisticated theoretical 

 evaluations of the behavior of two cylindrical bodies in beam seas and 

 to a combined theoretical and experimental study of an unusual con- 

 cept for a large expandable floating platform. 



The several studies are related because they all deal with 

 floating configurations with zero nominal speed through the water. Two 

 of the studies deal with the important problems of hydrodynamic inter- 

 actions, although the nature and extent, as well as the modes of in- 

 vestigations of the interactions, differ significantly. 



These studies represent a significant portion of the extensive 

 research and development work which has been done on ocean plat- 

 form behavior at Davidson Laboratory in recent years. They do not 

 relate specifically to ad hoc testing and evaluation of drilling plat- 

 forms and similar craft, but it is hoped (and anticipated) that the find- 

 ings reported will prove to be useful for practical design purposes. 



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