Multibody Interactions of Floating Bodies with Time-Domain Predictions

Abstract

The applications and computational capability of the three-dimensional transient numerical panel code ITU-WAVE using potential theory approximation is further extended for the effects of the multibody interactions in arrays with linear and square arrays. The transient wave-body interactions of first-order radiation and diffraction hydrodynamic parameters are solved as the impulsive velocity potential to predict impulse response functions (IRFs) for each mode of motion. It is shown that hydrodynamic interactions are stronger when the bodies in an array system are in close proximity and these hydrodynamic interactions are reduced considerably and shifted to larger times before decaying to zero when the separation distances are increased. The numerical predictions of the radiation (added-mass and damping coefficients) and exciting (superposition of diffraction and Froude-Krylov) forces are presented on each floating body in an array system and on a single structure considering array as a single floating body. Furthermore, the numerical experiment shows the hydrodynamic interactions are more pronounced in the resonant frequency region that are of important for fluid forces over multibodies, responses, and designs of multibody floating systems. The present numerical results of ITU-WAVE are validated against analytical, other numerical, and experimental results for single body, linear arrays (two, five, and nine floating bodies), and a square array of four truncated vertical cylinders.