Dynamic response analysis of mooring cables for floating offshore wind turbines under ocean currents using a perturbation-based finite difference method

Abstract

The mooring cable serves a critical function in connecting floating platforms to the seabed in offshore floating wind turbines. Its dynamic response under complex ocean current conditions significantly influences overall system performance, yet remains challenging to analyze effectively. This paper proposes an efficient dynamic model that incorporates hydrodynamic effects within a finite difference framework. The governing equations are first simplified into a first-order partial differential equation using the perturbation method, then discretized through the Keller-box scheme. To address the sensitivity to initial conditions and enhance computational efficiency, the Bisection method is employed for parameter determination. Numerical simulations demonstrate that the proposed approach achieves substantial improvements in computational efficiency while maintaining accuracy under wave and current loading. Systematic parametric analysis further reveals that cable stiffness and node discretization density markedly affect dynamic response, whereas other parameters exhibit comparatively minor influence. These findings provide valuable insights for optimizing mooring system design in floating offshore wind turbine applications.