English

Particle-based simulations of steady-state mass transport at high P\'eclet numbers

Fluid Dynamics 2015-10-20 v1 Soft Condensed Matter

Abstract

Conventional approaches for simulating steady-state distributions of particles under diffusive and advective transport at high P\'eclet numbers involve solving the diffusion and advection equations in at least two dimensions. Here, we present an alternative computational strategy by combining a particle-based rather than a field-based approach with the initialisation of particles in proportion to their flux. This method allows accurate prediction of the steady state and is applicable even at high P\'eclet numbers where traditional particle-based Monte-Carlo methods starting from randomly initialised particle distributions fail. We demonstrate that generating a flux of particles according to a predetermined density and velocity distribution at a single fixed time and initial location allows for accurate simulation of mass transport under flow. Specifically, upon initialisation in proportion to their flux, these particles are propagated individually and detected by summing up their Monte-Carlo trajectories in predefined detection regions. We demonstrate quantitative agreement of the predicted concentration profiles with the results of experiments performed with fluorescent particles in microfluidic channels under continuous flow. This approach is computationally advantageous and readily allows non-trivial initial distributions to be considered. In particular, this method is highly suitable for simulating advective and diffusive transport in microfluidic devices.

Keywords

Cite

@article{arxiv.1510.05126,
  title  = {Particle-based simulations of steady-state mass transport at high P\'eclet numbers},
  author = {Thomas Müller and Paolo Arosio and Luke Rajah and Samuel I. A. Cohen and Emma V. Yates and Michele Vendruscolo and Chrisopher M. Dobson and Tuomas P. J. Knowles},
  journal= {arXiv preprint arXiv:1510.05126},
  year   = {2015}
}