Motion characteristics of large arrays of modularized floating bodies with hinge connections

This paper investigates the hydroelastic response of a multi-patch floating photovoltaic (FPV) structure in water waves over a stepped seabed. The resonance conditions and underlying mathematical mechanism of FPV patches are explored based on the linear potential-flow theory and the thin-plate model. An implicit function of the open-water wavelength and the FPV patch's structural wavelength is derived. Resonance conditions occur in the FPV patch when the patch length and structural wavelength (rather than the water wavelength, as commonly believed) satisfy certain proportions. Mathematical derivations are conducted to interpret the value of each proportion. Two resonance conditions are recognized based on the mathematical structure of the solution. The effects of a stepped seabed and adjacent patches on the resonance conditions and hydroelastic behavior of FPV structures are also investigated. For a given stiffness parameter, the resonance conditions of FPV patches are solely determined by the water depth. The distance between adjacent patches does not alter the resonance conditions of each patch. Resonance occurs in the water body between two patches when the ratio of patch distance to water wavelength takes certain proportional values. A resonant water body tends to amplify the oscillation amplitude of both patches. However, when two FPV patches and a constrained water body reach their theoretical resonance conditions at the same time, the oscillation amplitudes of both the seaward patch and the constrained free surface are evidently suppressed. The transmitted waves of an FPV structure are largely determined by the dynamics of the leeward patch.

Resonance mechanism of hydroelastic response of multi-patch floating photovoltaic structure in water waves over stepped seabed

Zhang,

Wang,

Huang

et al. 2023

Analytical study on hydrodynamic performance of co-located offshore wind–solar farms

Zhu,

Shi,

Tao

et al. 2024

Based on linear potential flow theory, this study investigates the hydrodynamic performance of a co-located farm with an array of floating offshore wind turbines (FOWTs) and floating photovoltaics (FPVs). In this process, to evaluate the wave–structure interaction, domain decomposition and matched eigenfunction method are applied to address the boundary value problem for a complex-shaped co-located farm, and the velocity potential can be decomposed into radiation and diffraction problems. Under the framework of linearized theory, we establish the coupled motion equations by modeling rigid and articulated constraints to evaluate the kinematic response of the FOWTs and FPVs in the co-located farm. For such a system, a co-located farm consisting of an array of OC4-DeepCwind FOWTs and FPVs is proposed and investigated in this study. After running convergence analysis and model validation, the present model is employed to perform a multiparameter effect analysis. Case studies are presented to clarify the effects of solar platform geometric parameters (including column depth, thickness, radius, and total draft), articulated system, and shadow effect on the hydrodynamic behavior of wind and solar platforms. The findings elucidated in this work provide guidance for the optimized design of FPVs and indicate the potential for synergies between wind and solar energy utilization on floating platforms.

Motion characteristics of a modularized floating solar farm in waves

Wei,

Zou,

Zhang

et al. 2024

Modularized floating solar farms exhibit the potential to replace conventional steel-frame ones, effectively remedying hydroelastic issues of a very large floating structure through discrete modules with mechanical connections. However, the response of the discrete modules under cyclic wave loading has not been fully understood. This paper assesses the motion characteristics and expansibility of modularized floaters in waves, based on computational results from fluid–structural interaction simulations. A crucial factor, denoted as the ratio of frame length to wavelength R=Ls/λ, is determined to predict the motions of a large floating solar system in head waves. Results indicate that the motion characteristics is predictable based on the R value. The empirical relationship between the R value and the motion of every unit in an array is analyzed. In particular, the results calculated from using the multiple-rigid-bodies method are also compared with those from using the single-large-hydroelastic-body method, and it was found that these two results are similar when R > 1. This similarity allows for predicting the multi-hinged bodies' behavior in waves through a simplified hydroelastic approach. Overall, this study reports insights that are useful for the design and optimization of modularized solar farms and can help address cyclic loading and motion concerns for long-term durability.