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

HC nano-particle and Rarefied gas

Immersed boundary method

DNS

Författare

Ananda Subramani Kannan

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Vasilis Naserentin

Chalmers, Matematiska vetenskaper, Tillämpad matematik och statistik

Andreas Mark

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Dario Maggiolo

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Gaetano Sardina

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Srdjan Sasic

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Henrik Ström

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

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Ämneskategorier

Beräkningsmatematik

Strömningsmekanik och akustik

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Senast uppdaterat

2019-06-25