Motivation

Large-scale computational resources now enable the direct simulation of atomic systems, using realistic interatomic potentials. Molecular Dynamics (MD) simulations do not require any a priori model for the fluid, such as its equation of state, the transport coefficients, or a collision model. The interaction between the atoms is derived by some potential energy function, which is the only modeling effort required. Rapid advancements in the field of computational chemistry combined with continued advances in high performance computing may enable MD to be a very powerful technique to precisely investigate the highly complex nonequilibrium physics, found in high-speed flows, at the molecular level. Such MD simulations could then be used to inform DSMC collision models (a bottom-up approach), as opposed to developing them to match, in the continuum limit, the empirical laws used in CFD computations (a top-down approach). In general, if MD simulations are used to build DSMC collision models, for example, by providing the numerical value for certain parameters, or to determine a functional relation, then DSMC should reproduce the MD results very accurately, and more efficiently.

Results and Publications