2023/03/11 by Xinwei Cai, Zhen Li, Cai, Xinwei +3 · 2 citations
Engineering · #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics Simulations and Interactions #Granular flow and fluidized beds #Lattice Boltzmann Simulation Studies
paper · pdf · doi:10.48550/arxiv.2303.06327
openalex publication_date 2023/03/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We model a slip boundary condition at fluid-solid interface of an arbitrary geometry in smoothed particle hydrodynamics and smoothed dissipative particle dynamics simulations. Under an assumption of linear profile of the tangential velocity at quasi-steady state near the interface, an arbitrary slip length b can be specified and correspondingly, an artificial velocity for every boundary particle can be calculated. Therefore, b as an input parameter affects the calculation of dissipative and random forces near the interface. For b → 0, the no-slip is recovered while for b → ∞, the free-slip is achieved. Technically, we devise two different approaches to calculate the artificial velocity of any boundary particle. The first has a succinct principle and is competent for simple geometries, while the second is subtle and affordable for complex geometries. Slip lengths in simulations for both steady and transient flows coincide with the expected ones. As demonstration, we apply the two approaches extensively to simulate curvy channel flows, dynamics of an ellipsoid in pipe flow and flows within complex microvessels, where desired slip lengths at fluid-solid interfaces are prescribed. The proposed methodology may apply equally well to other particle methods such as dissipative particle dynamics and moving particle semi-implicit methods.