A novel multiphase DNS method for the resolution of Brownian motion in a weakly rarefied gas using a continuum framework
Paper in proceedings, 2019

In this paper, we formulate an Immersed boundary based direct numerical simulation (DNS) technique for resolving the particle-fluid coupling between a nano-particle and a (weakly) rarefied gas. Such a method resolves the mobility of these solid particles by incorporating the hydrodynamics of the fluid more rigorously within the conventional Langevin description of the system. We analyse the consequences of resolving the subsequent Brownian motion of spherical soot-like hydrocarbon (HC) nano-particles in an unbounded domain using such a framework. The proposed method is able to capture the transition from a particle-inertia dominated (highly correlated) ballistic regime (t^2) to a non-correlated diffusive one (2Dt as given by the Stokes-Einstein relation) and further accurately estimate the resulting diffusivity of the nano-particle. This method can be used within any multiphase DNS framework to reproduce the meandering motion of soot-like Brownian particles under similar conditions.

rownian motion

Immersed boundary method

HC nano-particle and Rarefied gas

DNS

Author

Ananda Subramani Kannan

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Vasilis Naserentin

Chalmers, Mathematical Sciences, Applied Mathematics and Statistics

Andreas Mark

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Fraunhofer-Chalmers Centre

Dario Maggiolo

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Gaetano Sardina

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Srdjan Sasic

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Henrik Ström

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

65

10 th International Conference on Multiphase Flow, ICMF 2019
Rio de Janeiro, Brazil,

Subject Categories

Computational Mathematics

Fluid Mechanics and Acoustics

More information

Latest update

9/12/2019