Fabien Thiesset (CNRS ICARE, Orléans). On the geometrical properties of turbulent premixed flames and other corrugated interfaces.

This study focuses on the geometrical properties of turbulent flame fronts and other folded interfaces. In this purpose, we use Proper Orthogonal Decomposition (POD) which is here applied to the interface spatial coordinates. The focus is mainly on the degree of roughness of these interfaces which is quantified through the scale dependence of their coverage arclength.

On the basis of an extensive experimental study using Mie scattering tomography measurements in a turbulent Bunsen Burner and data from the litterature, the present study addresses to the following issues.

1. Is the POD reliable for extracting quantitative informations on the geometrical properties of turbulent premixed flames? How does it compare to other fractal methods such as the caliper technique?

2. Does the scale distribution of wrinkling comply with scale-similarity? If yes, what are the relevant normalizing scales?

3. What is the ability of some existing empirical or phenomenological relations for predicting the fractal characteristics of corrugated flames?

4. Are there similar patterns in the folding distribution of different interfaces? Could they be represented by a unique heuristic phenomenology?