Abstract

The aim of hybrid methods in simulations is to communicate regions with disparate time and length scales. In this case, an inner area P with atomistic fluid description and an outer region C with continuum fluid dynamics description are connected. Over an overlapping region, the two descriptions of matter are matched. Consists of a two-way coupling system (C?P and P?C) that transmits fluxes of mass, momentum, and energy. The hybrid system that is given here makes two contributions. It first deals with erratic flows and, more crucially, with energy transfer between the C and P areas. Using stable and unsteady flows with various rates of mass, momentum, and energy exchange, the C?P coupling is evaluated here. Since they include all hydrodynamic modes, relaxing flows represented by linear hydrodynamics�including transverse and longitudinal waves�are the most illuminating. The cell-averaged Fourier components of the flow variables in the P region�velocity, density, internal energy, temperature, and pressure�evolve in excellent agreement with the hydrodynamic trends when the hybrid coupling scheme is used following the commencement of an initial disturbance. Additionally, it is demonstrated that the method maintains the proper rate of entropy creation. We go through some broad specifications for the coarse-grained length and temporal scales that result from the distinctive microscopic and hydrodynamic scales.

Description