title: Lattice-Boltzmann hydrodynamics of anisotropic active matter.
abstract: A plethora of active matter models exist that describe the behavior of self-propelled particles (or swimmers), both with and without hydrodynamics. However, there are few studies that consider shape-anisotropic swimmers and include hydrodynamic interactions. Here, we introduce a simple method to simulate self-propelled colloids interacting hydrodynamically in a viscous medium using the lattice-Boltzmann technique. Our model is based on raspberry-type viscous coupling and a force/counter-force formalism, which ensures that the system is force free. We consider several anisotropic shapes and characterize their hydrodynamic multipolar flow field. We demonstrate that shape-anisotropy can lead to the presence of a strong quadrupole and octupole moments, in addition to the principle dipole moment. The ability to simulate and characterize these higher-order moments will prove crucial for understanding the behavior of model swimmers in confining geometries.
authors.affiliation: Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Joost
authors.initials: J
authors.lastname: de Graaf
authors.affiliation: Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Henri
authors.initials: H
authors.lastname: Menke
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Arnold J T M
authors.initials: AJ
authors.lastname: Mathijssen
authors.affiliation: Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Fabritius
authors.affiliation: Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Holm
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Tyler N
authors.initials: TN
authors.lastname: Shendruk