UC Berkeley

We present a high-order accurate scheme for fully coupled

fluid-structure interaction problems. The fluid is discretized using a

discontinuous Galerkin method on unstructured tetrahedral meshes, and

the structure uses a high-order volumetric continuous Galerkin finite

element method. Standard radial basis functions are used for the mesh

deformation. The time integration is performed using a partitioned

approach based on implicit-explicit Runge-Kutta methods. The

resulting scheme fully decouples the implicit solution procedures for

the fluid and the solid parts, which we perform using two separate

efficient parallel solvers. We demonstrate up to fifth order accuracy

in time on a non-trivial test problem, on which we also show that

additional subiterations are not required. We solve a benchmark

problem of a cantilever beam in a shedding flow, and show good

agreement with other results in the literature.

In addition, we create several simulations which are motivated by

real-world phenomena. First, we investigate flow around a thin

membrane at high-angle of attack, demonstrating the ability of the

leading edge of the membrane to align with the incident flow. Examples

are provided in both two and three dimensions. Next, we consider

biologically inspired flight, by investigating wing-like structures

driven in a flapping motion in both two and three dimensions.

Finally, we demonstrate how the method may be used in acoustics

problems, simulating a tuning fork in three dimensions. Here we

accurately capture decay rates purely from the fluid-structure

interaction and without any damping coefficients built into the

structure model.