Time-dependent and outflow boundary conditions for Dissipative Particle Dynamics

JOURNAL OF COMPUTATIONAL PHYSICS

卷:230

Article

Lei, Huan¹  Fedosov, Dmitry A.^1,2  Karniadakis, George Em¹ 

[1] Brown Univ, Div Appl Math, Providence, RI 02912 USA

[2] Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany

关键词: No-slip;    Shear force;    DPD;    Navier-Stokes;    Unsteady flow;   

DOI  :  10.1016/j.jcp.2011.02.003

来源: Elsevier

【 摘 要 】

We propose a simple method to impose both no-slip boundary conditions at fluid-wall interfaces and at outflow boundaries in fully developed regions for Dissipative Particle Dynamics (DPD) fluid systems. The procedure to enforce the no-slip condition is based on a velocity-dependent shear force, which is a generalized force to represent the presence of the solid-wall particles and to maintain locally thermodynamic consistency. We show that this method can be implemented in both steady and time-dependent fluid systems and compare the DPD results with the continuum limit (Navier-Stokes) results. We also develop a force-adaptive method to impose the outflow boundary conditions for fully developed flow with unspecified outflow velocity profile or pressure value. We study flows over the backward-facing step and in idealized arterial bifurcations using a combination of the two new boundary methods with different flow rates. Finally, we explore the applicability of the outflow method in time-dependent flow systems. The outflow boundary method works well for systems with Womersley number of O(1), i.e. when the pressure and flowrate at the outflow are approximately in-phase. (C) 2011 Elsevier Inc. All rights reserved.

【 授权许可】

Free