Creating analytically divergence-free velocity fields from grid-based data

Bharath Ravu, Murray Rudman, Guy Metcalfe, Daniel R. Lester, Devang V. Khakhar

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

Abstract

We present a method, based on B-splines, to calculate a Ccontinuous analytic vector potential from discrete 3D velocity data on a regular grid. A continuous analytically divergence-free velocity field can then be obtained from the curl of the potential. This field can be used to robustly and accurately integrate particle trajectories in incompressible flow fields. Based on the method of Finn and Chacon (2005) [10]this new method ensures that the analytic velocity field matches the grid values almost everywhere, with errors that are two to four orders of magnitude lower than those of existing methods. We demonstrate its application to three different problems (each in a different coordinate system) and provide details of the specifics required in each case. We show how the additional accuracy of the method results in qualitatively and quantitatively superior trajectories that results in more accurate identification of Lagrangian coherent structures.
Original languageEnglish
Pages (from-to)75-94
Number of pages20
JournalJournal of Computational Physics
Volume323
DOIs
Publication statusPublished - 2016

Keywords

  • Divergence-free interpolation
  • Discrete velocity data
  • Vector potential
  • Lagrangian coherent structures

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