An overlapping domain technique coupling spectral and finite elements for fluid flow

• A new overlapping domain technique is proposed to couple SEM with FEM.
• The technique introduced is intended for FSI computations with 1000• Several benchmark computations have been performed to test the fluid–fluid coupling.
• SEM results in more accurate computations than FEM using less nodal points.
• The results demonstrate that the technique is accurate and stable.

Spectral elements are preferred for accurate prediction of transitional flows, whereas finite elements are better suited for, possibly non-smooth, deforming solid objects. A new overlapping domain technique is proposed that couples spectral and finite elements. This technique aims to efficiently capture the pressure jump and deformation rates of thin solids moving in a fluid. The solid object is fully embedded in a finite element fluid mesh and the coupling interface is situated in the fluid domain. The technique is particularly suited for simulation of cardiovascular fluid–structure interaction problems, such as flow through heart valves. In this paper the overlapping domain technique will be explained and several numerical benchmarks will be presented to test the fluid–fluid coupling between spectral and finite elements. The results obtained demonstrate that the technique is accurate and stable.