Numerical study of mean drift force on stationary flexible barge

In this study, a fully coupled fluid–structure interaction model was used to compute the mean drift force on a flexible barge under various wave conditions. The fluid domain was solved using a time domain B-spline 3-D Rankine panel method. The structural domain was modeled using a shell-element-based 3-D finite element model. The fluid model was coupled with the 3-D FE model via eigenvectors. Seakeeping analysis of the flexible body was performed by the fully coupled model. In the computation of drift force, two approaches were employed: a near-field method and a far-field method. The near-field method included an extension of the rigid body formula in the flexible body formula. The far-field method used the same formula for the rigid body and the flexible body. To the knowledge of the authors, it was not easy to find validation data for the mean drift force on a flexible barge. Therefore, an indirect validation was conducted by comparison of numerical results using a different approach. As a test model, a virtual barge model was used. The motion and mean drift force on the rigid barge were compared with the results of a commercial software, WADAM. The mean drift force on the flexible barge was compared to the results of the near-field and far-field methods.