Coupled fluid-solid interactions under shock wave loading

Fluid-solid interaction occurs in a wide variety of engineering applications such as blast response of structures or aeroelastic response of aircraft. An important class of fluid-solid interaction involves shock waves interacting with solid objects as in blast problems or ballistics problems. However, this class of problems has the potential for large relative motion between the fluid and the solid. Such large relative motion can be troublesome for computational schemes.; In this work, numerical methods are studied for problems involving large relative motion of the fluid and solid fields under shock wave interaction. Of particular interest, is the use of overlapping fluid and solid meshes. Overlapped meshes accommodate large relative motion without distortion of the fluid mesh. However, the fluid-solid interface arbitrarily cuts through the fluid elements. Identifying and enforcing boundary conditions at these internal interfaces on a fluid mesh is the primary focus of the research presented here.; A discontinuous Galerkin method has been developed to solve the Euler equations on an unstructured mesh. This solver was developed specifically to handle internal fluid-solid interfaces. These interfaces are represented by rigid, analytic surfaces. A level-set method based on a new super-sampled projection is used to identify edges of the fluid grid cut by the interface. Boundary conditions are enforced at the fluid-solid interface by modifying the fluxes computed at these cut edges. These fluxes are computed using a ghost-fluid method.The solver has been tested with a number of simulations containing both static and dynamic interfaces on the mesh. Results are presented for shock waves impacting static interfaces such as wedges and cylinders. Two and three-dimensional dynamic interface simulations are also presented involving shock waves interacting with high-speed projectiles.