TY - JOUR
T1 - Time line cell tracking for the approximation of lagrangian coherent structures with subgrid accuracy
AU - Kuhn, Alexander
AU - Engelke, Wito
AU - Rössl, Christian
AU - Hadwiger, Markus
AU - Theisel, Holger
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was partially funded by the German Federal Ministry of Education and Research under grant number 01LK1213A.
PY - 2013/12/5
Y1 - 2013/12/5
N2 - Lagrangian coherent structures (LCSs) have become a widespread and powerful method to describe dynamic motion patterns in time-dependent flow fields. The standard way to extract LCS is to compute height ridges in the finite-time Lyapunov exponent field. In this work, we present an alternative method to approximate Lagrangian features for 2D unsteady flow fields that achieve subgrid accuracy without additional particle sampling. We obtain this by a geometric reconstruction of the flow map using additional material constraints for the available samples. In comparison to the standard method, this allows for a more accurate global approximation of LCS on sparse grids and for long integration intervals. The proposed algorithm works directly on a set of given particle trajectories and without additional flow map derivatives. We demonstrate its application for a set of computational fluid dynamic examples, as well as trajectories acquired by Lagrangian methods, and discuss its benefits and limitations. © 2013 The Authors Computer Graphics Forum © 2013 The Eurographics Association and John Wiley & Sons Ltd.
AB - Lagrangian coherent structures (LCSs) have become a widespread and powerful method to describe dynamic motion patterns in time-dependent flow fields. The standard way to extract LCS is to compute height ridges in the finite-time Lyapunov exponent field. In this work, we present an alternative method to approximate Lagrangian features for 2D unsteady flow fields that achieve subgrid accuracy without additional particle sampling. We obtain this by a geometric reconstruction of the flow map using additional material constraints for the available samples. In comparison to the standard method, this allows for a more accurate global approximation of LCS on sparse grids and for long integration intervals. The proposed algorithm works directly on a set of given particle trajectories and without additional flow map derivatives. We demonstrate its application for a set of computational fluid dynamic examples, as well as trajectories acquired by Lagrangian methods, and discuss its benefits and limitations. © 2013 The Authors Computer Graphics Forum © 2013 The Eurographics Association and John Wiley & Sons Ltd.
UR - http://hdl.handle.net/10754/563145
UR - http://doi.wiley.com/10.1111/cgf.12269
UR - http://www.scopus.com/inward/record.url?scp=84894573291&partnerID=8YFLogxK
U2 - 10.1111/cgf.12269
DO - 10.1111/cgf.12269
M3 - Article
SN - 0167-7055
VL - 33
SP - 222
EP - 234
JO - Computer Graphics Forum
JF - Computer Graphics Forum
IS - 1
ER -