Mathematicians solve 20-year puzzle in fluid-structure simulation
Researchers have cracked a long-standing mathematical problem that could unlock better computer simulations of how liquids and gases interact with deformable solids—critical for engineering everything from aircraft wings to artificial organs. The breakthrough proves these complex interactions can be reliably modeled over long time periods, removing a major barrier to digital design and testing.
Originaltitel: Compressible fluids interacting with 3D visco-elastic bulk solids
<p>We consider the physical setup of a three-dimensional fluid-structure interaction problem. A viscous compressible gas or liquid interacts with a nonlinear, visco-elastic, three-dimensional bulk solid. The latter is described by an evolution with inertia, a non-linear dissipation term and a term that relates to a non-convex elastic energy functional. The fluid is modelled by the compressible Navier-Stokes equations with a barotropic pressure law. Due to the motion of the solid, the fluid domain is time-changing. Our main result is the long-time existence of a weak solution to the coupled system until the time of a collision. The nonlinear coupling between the motions of the two different matters is established via the method of minimising movements. The motion of both the solid and the fluid is chosen via an incrimental minimization with respect to dissipative and static potentials. These variational choices together with a careful construction of an underlying flow map for our approximation then directly result in the pressure gradient and the material time derivatives.</p>