Statistical mechanics of transport processes in active fluids. II. Equations of hydrodynamics for active Brownian particles

Abstract

We perform a coarse-graining analysis of the paradigmatic active matter model, active Brownian particles, yielding a continuum description in terms of balance laws for mass, linear and angular momentum, and energy. The derivation of the balance of linear momentum reveals that the active force manifests itself directly as a continuum-level body force proportional to an order parameter-like director field, which therefore requires its own evolution equation to complete the continuum description of the system. We derive this equation, demonstrating in the process that bulk currents may be sustained in homogeneous systems only in the presence of interparticle aligning interactions. Furthermore, we perform a second coarse-graining of the balance of linear momentum and derive the expression for active or swim pressure in the case of mechanical equilibrium.

Document Details

Document Type
Pub Defense Publication
Publication Date
Apr 24, 2019
Source ID
10.1063/1.5054912

Entities

People

  • Jeffrey M Epstein
  • Katherine Klymko
  • Kranthi K. Mandadapu

Organizations

  • Lawrence Berkeley National Laboratory
  • United States Department of Defense
  • United States Department of Energy
  • Yusuf Hamied Department of Chemistry

Tags

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Computational Fluid Dynamics (CFD)
  • Control Systems Engineering.