A Coupled Fluid-Structure Simulation Framework for Fracturing Solids in High-Atmosphere Applications

Hypersonic vehicles must at times fly through clouds of solid particulates. As a result of the high speeds encountered by these vehicles, the particulates, such as atmospheric ice and dust, can damage the thermal protection systems required to maintain vehicle integrity. Therefore, understanding of the damage potential of atmospheric particulates on hypersonic vehicles is an important part of mission planning. However, the effects of high-pressure, high-temperature gas in the shock layer on these particulates in their transit from freestream flow to the vehicle surface is currently not well-characterized. The high pressures encountered could potentially fracture the particulates before reaching the vehicle surface. Research into the simulation of fluid-structure interactions (FSI) is most often concerned with systems such as elastic solids in contact with incompressible, continuum fluid domains, but a method is proposed here which is able to simulate non-equilibrium flows interacting with fracturing solid objects. Fluids are modeled with the direct simulation Monte Carlo technique, and structures are modeled with the lattice particle method. The solid and fluid domains are coupled by the use of an adapted marching cubes algorithm. Verification of the lattice particle method implementation is presented, and results from two example FSI simulations are reviewed, both investigating the effects of normal shocks on spherical ice.