Title
Efficient FMM accelerated vortex methods in three dimensions via the Lamb-Helmholtz decomposition
Abstract
Vortex methods are used to efficiently simulate incompressible flows using Lagrangian techniques. Use of the FMM (Fast Multipole Method) allows considerable speed up of both velocity evaluation and vorticity evolution terms in these methods. Both equations require field evaluation of constrained (divergence free) vector valued quantities (velocity, vorticity) and cross terms from these. These are usually evaluated by performing several FMM accelerated sums of scalar harmonic functions. We present a formulation of vortex methods based on the Lamb-Helmholtz decomposition of the velocity in terms of two scalar potentials. In its original form, this decomposition is not invariant with respect to translation, violating a key requirement for the FMM. One of the key contributions of this paper is a theory for translation for this representation. The translation theory is developed by introducing ''conversion'' operators, which enable the representation to be restored in an arbitrary reference frame. Using this form, efficient vortex element computations can be made, which need evaluation of just two scalar harmonic FMM sums for evaluating the velocity and vorticity evolution terms. Details of the decomposition, translation and conversion formulae, and sample numerical results are presented.
Year
DOI
Venue
2013
10.1016/j.jcp.2013.01.021
Journal of Computational Physics
Keywords
DocType
Volume
scalar potential,scalar harmonic function,efficient vortex element computation,lamb-helmholtz decomposition,velocity evaluation,field evaluation,translation theory,vortex method,vorticity evolution term,efficient fmm,scalar harmonic fmm sum,numerical analysis,fast multipole method,vortices,technical report,velocity,harmonic functions,incompressible flow
Journal
240,
ISSN
Citations 
PageRank 
0021-9991
2
0.46
References 
Authors
8
2
Name
Order
Citations
PageRank
Nail A. Gumerov140440.62
Ramani Duraiswami21721161.98