Coupling strategies for hybrid molecular—continuum simulation methods

The paper presents numerical issues with regard to the development of hybrid molecular—continuum computational methods for macro and nanoscale modelling of nanoflows and materials. The implementation is based on a hybrid solution interface between the continuum and molecular regions. Two different approaches for the transfer of the mass, momentum, and energy fluxes onto the boundary of the molecular dynamics domain, are considered: (a) momentum transfer by force and (b) momentum transfer by velocity reversing. Simulations performed for a static fluid and free flow between molecular and continuum boundaries have shown that in the case of the momentum-transfer-by-force approach, the width of the relaxation zone depends linearly on the number of boundary atoms onto which the force is applied to, and for a free-flow this approach is numerically unstable. On the other hand, the momentum transfer by velocity reversing was found to lead to correct results with regard to energy conservation and variables distribution within the hybrid solution interface and was numerically stable both for static and free-flow test cases.

[1]  A. Patera,et al.  Heterogeneous Atomistic-Continuum Representations for Dense Fluid Systems , 1997 .

[2]  Eirik Grude Flekkøy,et al.  Hybrid model for combined particle and continuum dynamics , 2000 .

[3]  Ronald E. Miller,et al.  Atomistic/continuum coupling in computational materials science , 2003 .

[4]  Siegfried Schmauder,et al.  A New Method for Coupled Elastic-Atomistic Modelling , 1989 .

[5]  P. V. Coveney,et al.  USHER: An algorithm for particle insertion in dense fluids , 2003 .

[6]  G De Fabritiis,et al.  Multiscale modeling of liquids with molecular specificity. , 2006, Physical review letters.

[7]  Steve Plimpton,et al.  Fast parallel algorithms for short-range molecular dynamics , 1993 .

[8]  Peter V. Coveney,et al.  Hybrid molecular–continuum fluid dynamics , 2004, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[9]  P. Koumoutsakos,et al.  Hybrid atomistic-continuum method for the simulation of dense fluid flows , 2005 .

[10]  Alejandro L. Garcia,et al.  Adaptive Mesh and Algorithm Refinement Using Direct Simulation Monte Carlo , 1999 .

[11]  O'Connell,et al.  Molecular dynamics-continuum hybrid computations: A tool for studying complex fluid flows. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[12]  Peter S. Lomdahl,et al.  LARGE-SCALE MOLECULAR-DYNAMICS SIMULATION OF 19 BILLION PARTICLES , 2004 .

[13]  Geri Wagner,et al.  Coupling molecular dynamics and continuum dynamics , 2002 .

[14]  Gianni De Fabritiis,et al.  Energy controlled insertion of polar molecules in dense fluids. , 2004, The Journal of chemical physics.

[15]  J. Banavar,et al.  Computer Simulation of Liquids , 1988 .

[16]  P. Coveney,et al.  Continuum-particle hybrid coupling for mass, momentum, and energy transfers in unsteady fluid flow. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[17]  J Feder,et al.  Coupling particles and fields in a diffusive hybrid model. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.