A hybrid atomistic–continuum model for fluid flow using LAMMPS and OpenFOAM Original Research Article

A fully parallelized hybrid atomistic–continuum (HAC) model, built from the open source codes LAMMPS and OpenFOAM, is developed to resolve nanoscale features of fluid flow. The domain is decomposed into an atomistic domain, where individual atomic interactions are computed, and a continuum domain, where the Navier–Stokes equations are solved. The two domains are coupled through an overlap region in which the solutions in both domains are consistent. The accuracy of the HAC model is demonstrated through the simulation of sudden start Couette flow. The hybrid model is shown to reduce computation time by a factor of five for a 78 nm channel as compared to a fully-atomistic simulation; this speedup is expected to become even greater for larger systems.