This paper presents a discussion of the effect of including mooring line dynamics and riser friction on Spar response. Data from the Neptune Spar revealed that the heave motion of the vessel was considerably less than predicted by an uncoupled analysis. It was believed that the primary cause of the reduced heave was damping forces such as friction between the risers and the supporting guides and mooring line dynamic drag that were unaccounted for. A new analysis capability was subsequently developed to simultaneously predict the dynamic response of the vessel, mooring lines, and risers. Results of the coupled analysis reveal that mooring line dynamics and riser friction have significant effect on the Spar heave response. In this paper, comparison of coupled analysis results to Neptune Spar motions during Hurricane Georges will be presented. As a result of reduction in heave response, the draft of the Spar can be reduced. A coupled analysis of a shorter draft Spar is presented. Results for matthieu's instability problem, effect of coupling in different water depths and comparison of coupled response of classic versus truss Spar configurations are also presented. Coupled response of Spar and a second vessel moored together with chains is presented to demonstrate the multiple vessel simulation capability of the coupled analysis program.
Effects of Spar coupled analysis
2000
10 Seiten, 3 Quellen
Aufsatz (Konferenz)
Englisch