A constrained particle dynamics for continuum-particle hybrid method in micro- and nano-fluidics

Abstract

A hybrid method of continuum and particle dynamics is developed for micro-and nano-fluidics, where fluids are described by a molecular dynamics (MD) in one domain and by the Navier-Stokes (NS) equations in another domain. In order to ensure the continuity of momentum flux, the continuum and molecular dynamics in the overlap domain are coupled through a constrained particle dynamics. The constrained particle dynamics is constructed with a virtual damping force and a virtual added mass force. The sudden-start Couette flows with either non-slip or slip boundary condition are used to test the hybrid method. It is shown that the results obtained are quantitatively in agreement with the analytical solutions under the non-slip boundary conditions and the full MD simulations under the slip boundary conditions.

3D Coalescence Collision of Liquid Drops Using Smoothed Particle Hydrodynamics

“…The contribution of Tartakovsky & Meakin (2005) could be very useful when modeling the hydrodynamic interaction of drops in liquid emulsions. Combining these schemes with some continuousdiscrete hybrid approach (Cui et al, 2006;Koumoutsakos, 2005;Li et al, 1998;Nie et al, 2004;O'Connell & Thompson, 1995) it could be constructed an interesting model to discuss the collapse and disappearance of the interfacial film in emulsion media (Bibette et al, 1992;Ivanov & Dimitrov, 1988;Ivanov & Kralchevsky, 1997;Kabalnov & Wennerström, 1996;Sharma & Ruckenstein, 1987). Ivanov & Kralchevsky (1997) conducted a study on the possible outcomes for the collision of liquid droplets in emulsions.…”

The coupling of element-free Galerkin method and molecular dynamics for the incompressible flow problems

“…For the non-isothermal Couette flow problem, the atoms in the first layer are held fixed, while the atoms in the second layer are coupled to their nearest neighbors only including the solid atoms with stronger interaction. It is about nine times (Cui et al 2006) Microfluid Nanofluid (2011) 10:809-820 811 stronger than the interactions within the fluid, thus the crystal structure is retained (Liu et al 2007). …”

“…(Cui et al 2006) presents the schematic diagram of the coupling between the macro-scale numerical method and MD for solving the Couette flow problem, in which the technique of ''domain decomposition'' is used. From this schematic diagram we can know that the total computational domain is spatially divided into two parts: (1) the shading domain represented by the skew lines is the domain of macro-scale numerical method, which is named as continuum region; (2) the domain represented by the dots is the domain of MD, which is named as particle region.…”

A hybrid multiscale dissipative particle dynamics method coupling particle and continuum for complex fluid

“…The bridging domain multiscale method was developed by Xiao and Belytschko (2004), in which an overlapping domain consisting of both the molecules and continuum was used too. Cui et al (2006) developed a hybrid method of continuum and particle dynamics with a constrained particle dynamics, and used O'Connell and Thompson's model and Nie et al's model to simulate a sudden-start Couette flow with Newtonian fluid. Gu and Zhang (2006) developed a meshfree-based method for atomistic and continuum models.…”