Fluid-Structure Interaction — Aeroelasticity & VIV
One-way and two-way FSI, ALE formulation, partitioned coupling algorithms, flutter analysis, vortex-induced vibration, and added mass instability.
Articles in This Section
Quick Explainer
What is the added mass instability in strongly-coupled FSI?
When fluid and structural densities are comparable — blood in arteries, water around marine risers — the fluid exerts force proportional to structural acceleration, which depends on the fluid load. Weakly-coupled schemes solve fluid and structure once per time step sequentially, ignoring this feedback — the result is a numerical instability. Strong coupling iterates to convergence within each time step.
What is vortex-induced vibration and why is it dangerous for offshore structures?
VIV occurs when a bluff body in flow sheds vortices alternately from each side at the Strouhal frequency. When shedding frequency coincides with the structure's natural frequency, resonance occurs with large oscillation amplitudes. Marine risers, pipelines, and bridge cables in wind are classic VIV problems requiring time-accurate coupled CFD-structural analysis.