Jori Elan Ruppert-Felsot

Wavelet tools to study vortex bursting and turbulence production

Since there is not yet any agreement among specialists of turbulence about what coherent structures are and which method is the best to extract them, we propose an apophatic approach where, rather than stating what the coherent structures are, we make assumption about what they are not. We suppose that coherent structures are different from noise, and we thus define them as what remains after denoising. For the noise we use the mathematical definition of randomness, stating that a noise is homogeneously distributed in any functional basis.

Wavelet Analysis of Vortex Breakdown

We study the quasi-periodic turbulent bursting of a laboratory produced isolated vortex immersed in laminar flow. We analyze the experimentally measured flow field using orthogonal wavelets to observe the time evolution of the bursting. The discrete wavelet transform is used to separate the flow field into a coherent component, capturing the dynamics and statistics of the vortex during bursting, and an incoherent component, which is structureless and exhibits a different statistical behavior.

Analysis of a bursting vortex using continuous and orthogonal wavelets

We study the time evolution of the quasi-periodic bursting of a laboratory produced vortex using orthogonal and continuous wavelets.