Research objectives and content
This proposal develops and improves new wavelet methods initiated in DAMTP. These methods enable new refined characterisations of intermittency and of small-scale geometry of 1-dimension signals. They link the global intermittency to the local geometry of the flow structures. These methods will be developed in order to provide accurate systematic tools of data investigation and a systematic description of intermittency. These methods will also be extended to capture the local flow structures in 2-dimensional and 3-dimensional turbulence-data sets. These wavelet methods will be used on wide a range of well-resolved data obtained from Direct Numerical Simulations and laboratory experiments. The intermittency of the turbulence in the dissipation range will be investigated. We will systematically study the dependence on the Reynolds number and attempt to define the significance of the Taylor and Kolmogorov microscales. We will also describe the local topology of dissipation range structures. The methods will be improved in order to investigate the differences and similarities between Eulerian and Lagrangian intermittency. Training content (objective, benefit and expected impact)
As an important part of this proposal F. Nicolleau will be trained to wavelet methods and Lagrangian approaches which will complement his initial training on fractal and Eulerian approaches to turbulence. These wavelet approaches are rather unknown to the Laboratory of F Nicolleau in Lyon and will have a significant impact on the closure and combustion approaches developed in Lyon.