Objectif
The main goal of the project is to improve our knowledge of the mechanisms of the onset and development of coherent structures in laminar, transitional, and turbulent shear flows (boundary layer, Poiseuille and Couette flows, jets). Combination of experimental and numerical techniques will be used to address various topics: the nature and dynamical significance of coherent structures in shear flows and the role of vortex reconnection in turbulence cascade.
For realization of these goals two things will be developed:
(i) an adequate theory of 3-D macroscopic vortices with nonzero torsion of vortex lines as a suitable prototype for coherent structures (description of its self-induced motion, genesis and collapse of double-vortex filaments, interaction of vortex filament with a wall, pairing, merging and tilting of the vortices);
(ii) a true picture of a turbulent flow, which will be obtained only with help of advanced measurement technique (visualizations, LDA, PIV, stroboscopic velocity measurements and processing of signals for unsteady flows; hot-wire anemometers) as well as with help of accurate numerical simulation (a set of numerical codes for solution of 2D and 3D problems).
One more objective is to study the coherent structure onset and their features in flow on swept wing and to check the crossflow instability theories developed by other investigators. The investigation will be made how secondary, high frequency disturbances developed on the coherent structure result in turbulisation of a boundary layer on a swept wing.
The final purpose is to develop new acoustic methods for flow diagnostics and to determine active and passive methods of flow control based both on modification of the coherent structures and suppression of secondary disturbances developed on them.
A new level of our knowledge about the turbulence as the important problem of Theoretical Physics may become a prize of the project investigation.
Appel à propositions
Data not availableRégime de financement
Data not availableCoordinateur
7491 Trondheim
Norvège