title: Local membrane length conservation in two-dimensional vesicle simulation using a multicomponent lattice Boltzmann equation method.
abstract: We present a method for applying a class of velocity-dependent forces within a multicomponent lattice Boltzmann equation simulation that is designed to recover continuum regime incompressible hydrodynamics. This method is applied to the problem, in two dimensions, of constraining to uniformity the tangential velocity of a vesicle membrane implemented within a recent multicomponent lattice Boltzmann simulation method, which avoids the use of Lagrangian boundary tracers. The constraint of uniform tangential velocity is carried by an additional contribution to an immersed boundary force, which we derive here from physical arguments. The result of this enhanced immersed boundary force is to apply a physically appropriate boundary condition at the interface between separated lattice fluids, defined as that region over which the phase-field varies most rapidly. Data from this enhanced vesicle boundary method are in agreement with other data obtained using related methods [e.g., T. Krüger, S. Frijters, F. Günther, B. Kaoui, and J. Harting, Eur. Phys. J. 222, 177 (2013)10.1140/epjst/e2013-01834-y] and underscore the importance of a correct vesicle membrane condition.
authors.affiliation: Materials & Engineering Research Institute, Sheffield Hallam University, Howard Street S1 1WB, United Kingdom.
authors.forename: I
authors.initials: I
authors.lastname: Halliday
authors.affiliation: Materials & Engineering Research Institute, Sheffield Hallam University, Howard Street S1 1WB, United Kingdom.
authors.forename: S V
authors.initials: SV
authors.lastname: Lishchuk
authors.affiliation: Materials & Engineering Research Institute, Sheffield Hallam University, Howard Street S1 1WB, United Kingdom.
authors.forename: T J
authors.initials: TJ
authors.lastname: Spencer
authors.affiliation: Istituto per le Applicazioni del Calcolo-CNR, Via dei Taurini 19-00185, Roma, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pontrelli
authors.affiliation: Department of Cardiovascular Science, and Insigneo Institute of In Silico Medicine, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, United Kingdom.
authors.forename: P C
authors.initials: PC
authors.lastname: Evans