The mixing of scales in shearless turbulent flow

The objective of this experience is to study an example of complex turbulen t flow produced by two coflows with the same velocity which presents a mixi ng of scales. This type of flow produces spectral perturbations with intera ctions between structures with different sizes. The experimental system pro duces the mixing of a primary pow into two secondary flows, these flows are supplied by two types of honeycombs producing turbulence and that can be d ifferently combined. The motivation of this study is the development of tur bulence models applicable in non-equilibrium situations. The experimental c ontribution presented here is aimed at describing the effects of the honeyc ombs on spectral distributions. (C) 2000 Academie des sciences/Editions sci entifiques et medicales Elsevier SAS.