Most single-reed woodwind instrument models rely on a quasistationary approximation to describe the relationship between the volume flow and the pressure difference across the reed channel. Semiempirical models based on the quasistationary approximation are very useful in explaining the fundamental characteristics of this family of instruments such as self-sustained oscillations and threshold o...

In this work, we compare different mesh moving techniques for monolithically-coupled fluid-structure interactions in arbitrary Lagrangian–Eulerian coordinates. The mesh movement is realized by solving an additional partial differential equation of harmonic, linear-elastic, or biharmonic type. We examine an implementation of time discretization that is designed with finite differences. Spatial d...

The design of phononic crystals and acoustic metamaterials with tunable and adaptive wave properties remains one of the outstanding challenges for the development of next generation acoustic devices. We report on the numerical and experimental demonstration of a locally resonant acoustic metamaterial with dispersion characteristics, which autonomously adapt in response to changes of an incident...

This contribution is the second part of two papers on the Fully Eulerian formulation for fluid-structure interactions (fsi). We present different fsi applications using the Fully Eulerian scheme, where traditional interface-tracking approaches like the Arbitrary LagrangianEulerian (ALE) framework show difficulties. Furthermore, we present examples where parts of the geometry undergo a large mot...

We present a procedure to adapt and repair meshes in the general solution of Navier–Stokes incompressible and compressible fluid flows, including structural interactions. For fluid-structure interactions, FSI, the fluid is described by an arbitrary-Lagrangian–Eulerian formulation fully coupled to general solids and structures described by Lagrangian formulations. The solids and structures can u...

In this thesis, mixed primitive variable based finite element formulations are developed to solve linear and nonlinear fluid-structure interaction problems involving incompressible (or almost incompressible) fluid models. The mixed elements are used according to the inf-sup condition. It is pointed out that along the fluid-structure interfaces, different coupling conditions can be used accordin...

We present two methods for calculating resonant frequencies and mode shapes for fluid-structure vibration problems. We model the fluid-structure interaction problem using the #-V-P, finite element technique. This eigenproblem is more complicated than for ordinary structural analyses, as the formulation produces a quadratic eigenproblem (similar to those for gyroscopic systems). We derive proper...

In computation of fluid-structure interactions, we use mesh update methods consisting of mesh-moving and remeshing-as-needed. When the geometries are complex and the structural displacements are large, it becomes even more important that the mesh moving techniques are designed with the objective to reduce the frequency of remeshing. To that end, we present here mesh moving techniques where the ...

The paper presents a novel method for numerically modelling fluid-structure interactions. The method consists of solving the fluid-dynamics equations on an extended domain, where the computational mesh covers both fluid and solid structures. The fluid and solid velocities are relaxed to one another through a penalty force. The latter acts on a thin shell surrounding the solid structures. Additi...