Enabling Large-Scale Simulations of Flows Driven by Atomistic Effects

Hydrodynamic flows can be strongly influenced by molecular effects. Nonequilibrium behavior encountered in phase transitions, chemical reactions and diffusion processes fundamentally alter the fluid, thereby affecting the flow field. In particular, capturing an accurate flow field response in high-energy-density applications, such as inertial confinement fusion experiments, presents several major challenges. Significant advances in modeling these extreme conditions are achieved by coupling macroscopic solvers with atomistic simulations, such as molecular dynamics. However, the practicality of this approach is limited by the high computational costs of concurrently running molecular models with the flow solver. We present a strategy that allows continuum-atomistic frameworks to extend far into macroscopic length and time scales. By leveraging exascale computing architectures to optimize the balance between performance and accuracy, we achieve large-scale simulations. This contributes substantially to the effort of gaining first-principle insight into the material behavior of hydrodynamic models.

 

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, release number LLNL-ABS-867137.