Insight into Hydrodynamic Damping of a Segmented Barge Using Numerical Free-Decay Tests

Abstract

Natural vibrations of a segmented and a monohull barge are analysed to compare influences of hydrodynamic damping on the dynamic responses of two different models. The influence of water flow around and between barge segments on hydrodynamic damping was investigated by simulating free-decay tests using a URANS method. Fluid forces were fed into the modal solver, which allows for efficient deformation of the structure without full resolution of structural equations. Verification of the coupled solver was performed by reproducing the model experiments of a segmented barge. Comparison of segmented and monohull results clarified the impact of gaps between barge segments, i.e., how the energy dissipates because of large pressure gradients within and around gaps, and additional free-surface movement. This insight of higher damping should be taken into account for model tests of segmented floating structures, such as wave-energy-converting systems.

Keywords

• segmented barge
• hydrodynamic damping
• modal analysis
• CFD
• FSI