Turbulence in fluid flows is one of the most intriguing problems of physics, by the nature and great difficulty of fundamental questions it raises, and by its numerous essential practical effects in hydraulics, aerodynamics, combustion, acoustics, climate and environmental studies, and astrophysics. These applications induce an urgent need to predict and control its effects. During these last ten years, new theoretical approaches, either statistical or deterministic, sometimes borrowed to theoretical physics and statistical thermodynamics, have appeared.
The time has come to assess these methods, especially in the light of new numerical methods (large-eddy simulations ), or signal-processing tools (wavelet analysis, proper orthogonal decompositions). All these reasons motivate the project of an extended Summer School on Turbulence in Les Houches. This school will have a strong theoretical kernel, with emphasis put on questions such as large-scale organization, universality, symmetry breaking, mixing, and dislocations. Emphasis will be also put on new numerical tools (with application to industrial modelling in particular) and recent experimental advances. The coordinator and members of the scientific committee have outstanding records in the field, and there is no doubt that this interdisciplinary programme will meet a great interest from young researchers in Fluid Mechanics, Condensed-Matter Physics, Applied Mathematics and Environmental Sciences.