- Title: Metoder för virvelidentifiering
- Abstract: Initially, this paper presents an overview of the existing methods used for the identification of vortices, attempting to point out their different strengths and weaknesses. In addition, a new method is proposed to iden- tify vortices directly from velocity field information. It defines a point inside a vortex as a point around which there is rotation. By looking at the velocity directions of the neighbourhood of a point we decide if there is rotation. A measure of the strength of rotation at the point is also introduced based on the magnitude of the velocity components in the neighbourhood. The method is tested on simulated data and per- forms well. Finally a Lagrangian identification method (Direct Lyapunov Exponents) is used to attempt to calibrate the λ2 -criterion in order to match an objectively defined edge. The results here show that it might not be possible to find a λ2 threshold to match edges found using the DLE method.
- Start Date: June 1, 2012
- Supervisor: Alexandros Sopasakis
- Student: Vivianne Holmén
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Last update: 2013-04-11
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