2024 Volume 40 Pages 181-187
The effects of wave overtopping and sloshing on the second-order wave exciting forces of a barge-type floating structure with a moonpool and the applicability of weak nonlinear potential theory are investigated. The weak nonlinear potential theory can be applied to estimate the second-order sum frequency wave exciting forces under the condition that no wave overtopping over the floating structure occurs. On the other hand, the second-order sum frequency wave exciting forces increase due to wave overtopping. As a result, it is confirmed that the total wave exciting forces may greatly exceed the first-order component. It is also confirmed that the weak nonlinear potential theory can roughly estimate the steady wave drifting forces under conditions that no wave overtopping over the floating structure occurs. When wave overtopping occurs, the steady wave drifting forces increase in some frequency bands, but in other frequency bands, the steady wave drifting forces tend to decrease with the increase in wave height.