FINITE TIME LYAPUNOV EXPONENTS AND EXTREME CONCENTRATION FLUCTUATIONS IN 2D TURBULENCE etc15 Tracking Number 9Presentation: Session: Lagrangian aspects of turbulence 4 Room: Room F Session start: 10:30 Fri 28 Aug 2015 Hua Xia hua.xia@anu.edu.au Affifliation: The Australian National University Nicolas Francois nicolasfrancois2002@yahoo.fr Affifliation: The Australian National University Horst Punzmann horst.punzmann@anu.edu.au Affifliation: The Australian national University Kamil Szewc kamil.szewc@gmail.com Affifliation: Polish Academy of Sciences Michael Shats michael.shats@anu.edu.au Affifliation: The Australian National University Topics: - Transport and mixing, - Lagrangian aspects of turbulence Abstract: The Finite time Lyapunov exponent (FTLE) has been investigated in detail in laboratory 2D experiments. The balance of the forward and backward FTLE suggests the incompressible nature of the turbulence in both the electromagnetic and Faraday wave driven experiments. The tail in the PDF of the FTLE field has been shown to be correlated with the extreme concentration of the passive scale, the ‘unmixing’ event. |