An integrated boundary approach for colloidal suspensions simulated using smoothed dissipative particle dynamics

Journal Article · Sat Nov 24 00:00:00 EST 2018 · Computers and Fluids

DOI:https://doi.org/10.1016/j.compfluid.2018.11.025· OSTI ID:1484642

Petsev, Nikolai Dimitrov ^[1]; Leal, L. Gary ^[2]; Shell, M. Scott ^[2]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ. of California, Santa Barbara, CA (United States)

We report that in particle-based continuum solvers such as smoothed particle hydrodynamics (SPH) and smoothed dissipative particle dynamics (SDPD), one of the most significant challenges is the treatment of solid boundaries like walls and colloidal particles, whose presence leads to a truncation of the integral approximation, and hence, error in the numerical solution. In this work, we describe an integrated boundary framework for modeling colloidal suspensions composed of rigid spherical particles. The integral corresponding to the colloid's contribution is analytically evaluated, giving a simple and computationally inexpensive approach relative to conventional boundary particle techniques. We formulate a thermodynamically-consistent version of this top-down method for mesoscale simulations, in which the fluid exchanges momentum with the suspended particles due to thermal fluctuations, giving a framework for modeling the dynamics of colloids at arbitrary Reynolds and Péclet numbers. The resulting evolution equations are validated for a single colloidal particle in a fluid at constant temperature. This simple approach requires ~ N_c (p/m) R$$2\atop{c}$$ fewer pair force calculations relative to traditional boundary particle strategies, where N_c is the number of colloids in the system, R_c is the colloid radius, ρ is the colloid mass density, and m is the mass of the SDPD particles. Additionally, the use of integrated boundaries removes the need for rigid body constraint dynamics, giving an elegant and efficient basis for large-scale simulations of colloidal suspensions that is general and does not make any physical assumptions about the flow.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1484642
• Report Number(s): LA-UR--18-22657
• Journal Information: Computers and Fluids, Journal Name: Computers and Fluids Vol. 179; ISSN 0045-7930
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
colloids
hydrodynamics
smoothed dissipative particle dynamics
suspensions