Self-organization

Overview  

Lead: Alain Pocheau

IRPHE
Technopole de Chateau Gombert
49, rue Joliot Curie
B.P. 146
13384 Marseille Cedex 13
Tel: +33 (0)4 13 55 20 20
Fax: +33 (0)4 13 55 20 01

1.    Team Members 

Permanent Staff:

Doctoral Students:

  • Edouard Beauvier

News: Thesis Proposals and Internships

2.    General Overview

The Self-organization team studies systems exhibiting spatiotemporal organization and structures resulting from a nonlinear dynamic. Experimental systems studies include solidification interfaces, reactive fronts, and elastic systems.

3.    Primary Research Topics

 

Spatiotemporal dynamics of fronts

* Crystalline Growth: The manner in which a material solidifies is crucial to its physical properties, its quality, and its mechanical strength. As its solidification takes place through an advancing interface, it leaves behind indelible marks on the solid phase (microsegregation). It is essential to understand the phenomena that govern the shape and dynamics of these interfaces for two reasons: first, for its relationship to the fundamentals of nonequilibrium interfaces and second, to understand the microsegregation process.

Contacts: J. Deschamps, M. Georgelin and A. Pocheau

Two sample publications:

  • J. Deschamps, M. Georgelin, A. Pocheau Growth directions of microstructures in directional solidification of crystalline materials. Phys. Rev. E 78: 011605 (2008).
  • A. Pocheau, S. Bodea, M. Georgelin. Self-organized dendritic side-branching in directional solidification: side-branch coherence within uncorrelated bursts. Phys. Rev. E 80: 031601 (2009)

* Propagation of a front in structured flow: The classic application of front propagation in a structured environment is turbulent combustion. This is also an example of abnormal transport. However, the effect of the structure (here advection by a vortex lattice) is not sufficiently understood, even in laminar situations. To study it without the secondary effect of the reaction below the front, we have developed an athermic self-catalyzing reaction solution. Electro-convection was introduced into the environment using a counter-rotating vortex network. The front propagation is thereby amplified, as expected, however it is done so in a fashion that is yet to be explained.

Contacts: S. Bodea and A. Pocheau

Two sample publications:

  • A. Pocheau, F. Harambat. Effective front propagation in steady cellular flows: a least time criterion. Phys. Rev. E 73: 065304(R) (2006)
  • A. Pocheau, F. Harambat. Front propagation in a laminar cellular flow: shapes, velocities and least time criterion. Phys. Rev. E 77: 036304 (2008)