08-10-2026 - Lecture Hall C

Postdoc Presentation

Computational Fluid-Structure Interaction: Coupled High-Fidelity Solvers and Structure-Preserving Lagrangian Discretisations

Suyash Shrestha

Fluid–structure interaction (FSI) problems, such as aeroelastic flutter, wind turbine blades under extreme loads, and flexible solar panels floating on the water surface, require numerical tools that are both accurate and robust. In this talk, I present two complementary routes towards high-fidelity FSI simulation, linked by how the conservation laws are derived in different frames of reference.
The first approach is application-oriented and partitioned. An MFEM-based incompressible flow solver, using a residual-based variational multiscale (RBVMS) formulation in an arbitrary Lagrangian–Eulerian (ALE) framework, is coupled to a structural solver through the preCICE library. The approach is demonstrated on the perpendicular flap benchmark, illustrating the practical challenges of coupling high-fidelity fluid and structural solvers.
The second approach is more theoretical and centres on a structure-preserving monolithic formulation. Both the fluid and solid are described in a Lagrangian frame, in which the convective terms vanish, and the equations are pulled back to a fixed reference configuration. The resulting variational formulation is derived from the minimisation of a Hamiltonian. A structure-preserving discretisation then leads to a fully coupled scheme that conserves mass, momentum, and energy at the discrete level. This provides a unified framework for structure-preserving discretisation of coupled multi-physics problems.