An Arbitrary Lagrangian-Eulerian (ALE) Finite Element Potential Flow Solver for Fully Nonlinear Free Surface Flows and Wave-Structure Interactions in the Time Domain
摘要
A fully nonlinear potential flow (FNPF) solver has been developed using the Finite Element Method (FEM) to simulate time-domain interactions between free-surface waves and marine structures. The ALE framework is implemented alongside a segment spring analogy-based moving mesh strategy to accurately track evolving free surfaces and moving boundaries of floating bodies. The solver employs a preconditioned conjugate gradient method to efficiently resolve the resulting sparse, symmetric linear system at each time step. Temporal evolution is managed through a standard fourth-order Runge-Kutta scheme, while Chebyshev 5-point smoothing suppresses non-physical saw-tooth instabilities. The solver’s performance and reliability are verified through comprehensive benchmark tests, including free-surface sloshing, nonlinear wave propagation, and wave-structure interactions with submerged or floating bodies. Furthermore, the study explores a modified potential flow model incorporating a quadratic damping term to address viscous effects in gap/moonpool resonance problems.