Toward a Lagrangian Vector Field Topology

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Date
2010
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association and Blackwell Publishing Ltd.
Abstract
In this paper we present an extended critical point concept which allows us to apply vector field topology in the case of unsteady flow.We propose a measure for unsteadiness which describes the rate of change of the velocities in a fluid element over time. This measure allows us to select particles for which topological properties remain intact inside a finite spatio-temporal neighborhood. One benefit of this approach is that the classification of critical points based on the eigenvalues of the Jacobian remains meaningful. In the steady case the proposed criterion reduces to the classical definition of critical points. As a first step we show that finding an optimal Galilean frame of reference can be obtained implicitly by analyzing the acceleration field. In a second step we show that this can be extended by switching to the Lagrangian frame of reference. This way the criterion can detect critical points moving along intricate trajectories. We analyze the behavior of the proposed criterion based on two analytical vector fields for which a correct solution is defined by their inherent symmetries and present results for numerical vector fields.
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@article{
10.1111:j.1467-8659.2009.01686.x
, journal = {Computer Graphics Forum}, title = {{
Toward a Lagrangian Vector Field Topology
}}, author = {
Fuchs, Raphael
 and
Peikert, Ronny
 and
Kemmler, Jan
 and
Schindler, Benjamin
 and
Waser, Juergen
 and
Sadlo, Filip
 and
Hauser, Helwig
}, year = {
2010
}, publisher = {
The Eurographics Association and Blackwell Publishing Ltd.
}, ISSN = {
1467-8659
}, DOI = {
10.1111/j.1467-8659.2009.01686.x
} }
Citation