Abstract
A pontoon type Very Large Floating Structure (VLFS) is expected to be implemented in the near future. Design of mooring system of VLFS requires an estimate of slowly-varying wave drift force. However, slowly-varying wave drift force on elastic VLFS has not been precisely computed yet. Slowly-varying wave drift force is second order wave force with respect to the wave height. Computation of second order wave force is very complicated and difficult because it requires computation of second order velocity potential. The authors have resolved this problem by using assistant radiation potential method, restricting the model for analysis to a pontoon type VLFS. In this paper, computation of slowly-varying wave drift force on elastic VLFS has been made, and comparison between direct computation and well-known approximation (Newman's approximation) is presented.
