New modified weight function for the dissipative force in the DPD method to increase the Schmidt number

Abstract

To simulate liquid fluid flows with high Schmidt numbers (Sc), one needs to use a modified version of the Dissipative Particle Dynamics (DPD) method. Recently the modifications made by others for the weight function of dissipative forces, enables DPD simulations for Sc, up to 10. In this paper, we introduce a different dissipative force weight function for DPD simulations that allows achieving a solution with higher values of Sc and improving the dynamic characteristics of the simulating fluid. Moreover, by reducing the energy of DPD particles, even higher values of Sc can be achieved. Finally, using the new proposed weight function and kBT = 0.2, the Sc values can reach up to 200.

Simulation of high Schmidt number fluids with dissipative particle dynamics: Parameter identification and robust viscosity evaluation

“…The effect of this modification was the increase of the fluid viscosity, allowing to investigate higher Sc numbers than standard DPD with a comparable computational effort. Another modification to the weighting function was proposed by Yaghoubi and coworkers 17 . The drawback of these approaches, as in standard DPD, is the lack of shearing dissipation which has a great impact on the resulting viscosity of the simulated DPD fluid.…”

Coarse Grained Modeling of Multiphase Flows with Surfactants

“…DPD simulation has been criticized for artifacts, especially in dynamic behavior as the Schmidt number in standard DPD is close to 1, which is ideal for gases. An alternative to standard DPD has been suggested as LA-DPD [ 35 , 36 ], but using the standard DPD does not appear to be the reason for micelle formation below the CMC observed herein. For no flow or for Couette flow, the surfactants did not aggregate in one location of the interface to create micelles.…”

Accurate and efficient splitting methods for dissipative particle dynamics

“…In the current article, we demonstrate that the accuracy and efficiency of DPD simulations can be substantially improved in a wide range of the friction coefficients, especially in the extremely large friction limit (i.e, γ = 450) that corresponds to a fluid-like Schmidt number (i.e., Sc ≈ 1016). It is worth mentioning that the Schmidt number can be varied by either modifying the weight function [15,61] or using alternative approaches (e.g., LA and NHLA). However, in the current article we restrict our attention on the standard DPD formulation as it is by far the most popular and studied approach.…”