Hybrid finite element/molecular dynamics simulations of aluminum particle wall collisions

A hybrid finite element/molecular dynamics (FEM/MD) simulation was developed to simulate the collisions of micron sized aluminum particles with a nickel wall in a high-pressure liquid oxygen environment such as could be found in a liquid rocket engine. The finite element method was chosen in order to model full sized (100-500 micron diameter) aluminum particles. Molecular dynamics is used to accurately simulate the physics occurring at the contact point between the sphere and the wall: the collision dynamics, aluminum fracture and heating up, and subsequent initiation of aluminum-oxygen reactions on the surface of the sphere. The two simulation regimes are coupled by providing boundary conditions for each other. Initial results show the heating of the aluminum surface due to the collision of the aluminum particle with the wall at an impact velocity of 500 m/s.