EdgeCFD-ALE: A Stabilized Finite Element System for Fluid-Structure Interaction in Offshore Engineering

Abstract

This work presents the development of EdgeCFD-ALE, a finite element system for complex fluid-structure interactions designed for offshore hydrodynamics. Sloshing of liquids in tanks, wave breaking in ships, offshore platforms motions and green water on decks are important examples of these problems. The software uses edge-based parallel stabilized finite elements for the Navier-Stokes equations and the Volume-Of-Fluid method for the free-surface, both described by an Arbitrary Lagrangian Eulerian (ALE) formulation. Turbulence in is treated by a Smagorinsky model. Mesh updating is accomplished by a parallel edge-based solution of a non-homogeneous scalar diffusion problem in each spatial coordinate. Boundary conditions involve the motion of the immersed body’s surface, i.e., the fluid-structure interface, taken as the Lagrangian portion of the domain in the overall problem. The simulation capabilities of the present software are demonstrated in the solution of two problems, the interaction of two cylinders in tandem and the free fall of a sphere.