IUTAM Symposium on

Unsteady Separated Flows and their Control

Chandris Dassia Hotel, Corfu, Greece, 18/22 June 2007

Chairmen, and Scientific Editors of this Volume

General context of this symposium

This IUTAM Symposium concerns an important topic in Theoretical and Applied Mechanics nowadays. It aims at achieving a unified approach which will regroup the knowledge coming from theoretical, experimental, numerical simulation, modeling and flow-control aspects of separated unsteady flows with respect to incompressible and compressible flow regimes. The subject areas are receiving a great deal of impetus from international research groups, stimulated by major research programs related to this topic, involving major industrial companies especially in Aeronautics in various countries and by heading Government Programs. It aims to bring together the groups of researchers working on the problems related to the understanding and the prediction of unsteady, separated flows. This symposium is inspired from a previously held IUTAM symposium on unsteady separated flows in Toulouse, in 2002 by the present host Institution, a symposium that has been quite a success in the field. The present IUTAM symposium is an essential extension of the topic to control theory and applications in respect of unsteady separated flows.

The symposium of 2007 will address physical aspects of the dynamics related to unsteady separation in incompressible flows and flows under compressibility effects, and the state of the art methods for modelling these kinds of flows in high Reynolds numbers. Special attention will be paid to control theory and applications, especially including feed-back effects for the attenuation of unsteadiness and of flow separation. The understanding of the flow-physics and their efficient turbulence modelling remains a serious problem in a number of engineering applications, including Aeronautics and Aeroelasticity. Furthermore, the study of advanced flow modelling techniques, especially to control high-Reynolds number transitional and turbulent flows involving unsteady separation, is a crucial need in the above-mentioned domains of fundamental and applied research nowadays.

It is intended that people working in experimental investigation of unsteady separated flows, those working in the numerical simulation and turbulence modelling of these flows and those working in the domain of control theory should attend in order to stimulate the discussion in advancing the physical analysis of the related mechanisms and therefore to offer improvement in modelling and control of important unsteady phenomena arising in this class of flows. In this way, the symposium will contribute to a better insight of this important category of flows from a fundamental and applied research point of view by means of a synergy among the three main approaches: theoretical, experimental and prediction methods.

The Symposium will start on Monday, 18 June 2007 and will end on Friday, 22 June. It will consist of single plenary sessions with invited lectures (45 minutes), selected oral presentations (15 minutes), discussions on special topics and posters. There will be an attribution of best poster award, as in the IUTAM 2002 Symposium.

Symposium languages:

The official language for the Symposium is English

Scope

The physical mechanisms related to the onset of unsteady separation and of its control are key features for the understanding of fundamental aspects related to the dynamics of the near wall region and for the suppression of nuisance effects related with the flow unsteadiness (noise, loss of lift, dip-flutter, buffeting phenomenon…). A thorough knowledge of the physical mechanisms involved in the unsteady separation is a prerequisite for the appropriate modeling of related flows that have a crucial importance in major industrial applications. The reasons for the appearance of unsteady separation are due to inherently unsteady effects arising from the amplification of instabilities and to forcing factors responsible for creation of adverse pressure gradients, leading to detachment and to a roll-up process.
These effects are of major interest to be analyzed in the context of incompressible, subsonic, transonic and supersonic flow regimes. In particular, the influence of compressibility on unsteady separation will be of interest in the present symposium.
The effects of unsteady separation on the global and local parameters of the flow are of considerable interest in the mentioned domains and are directly linked to the kind of coherent structures formed downstream and to feedback mechanisms between the upstream and downstream separation regions. The advances in the understanding of the physical mechanisms related to these unsteady phenomena are of great importance to achieve appropriate control methods to attenuate/inhibit the instability and the onset of turbulence. Advanced control methods will be examined in respect of their efficiency in attenuating/suppressing the unsteady separation, the flow-induced vibrations as well as the transonic regime unsteady phenomena related to buffeting and dip-flutter.

The main objectives on which the present symposium focuses are listed below.

• Experimental techniques for the dynamics of separation

• Theoretical aspects of flow separation and analytical approaches

• Instability and Transition

• Compressibility effects related to unsteady separation

• Direct and Large Eddy Simulation of unsteady separated flows

• Statistical and hybrid Turbulence Modelling of unsteady separated flows

• Theoretical and industrial aspects of unsteady separated flow control

The Symposium consists of single plenary sessions with invited lectures, selected oral presentations, discussions on special topics and posters. The short programme is available here and the detailed programme is displayed in the next page.

The chairmen and the scientific committee thank the participants for their venue, their contribution and they wish a very successful symposium.
 
 

Scientific Committee

Invited key-note speakers

Host Institution

The host Institution is the Institut de Mécanique des Fluides de Toulouse (IMFT), Unité Mixte de Recherche N°5502,  CNRS / INPT / UPS,affiliated with: the French « Centre National de la Recherche Scientifique », the « Institut National Polytechnique de Toulouse » and the « Université Paul Sabatier ».

The Symposium is grateful to the IUTAM Committee for their support and for having attributed the IUTAM label to the symposium’s topic, as well as to the to the Director of IMFT, Dr. J. Magnaudet, to the President of INPT, Prof. Casamata, and to the President of UPS, Prof. Jean-François Sautereau, for their support.

Local organising committee

M. Braza, President,	IMFT
P. Chassaing,	IMFT
G. Harran,	IMFT
A. Sevrain,	IMFT
S. Saintlos Brillac,	IMFT
W. Haase,	EADS Münich
Y. Hoarau,	Univ. Strasbourg
M. Sabater,	IMFT
G. Martin,	IMFT
D. Bourrel,	IMFT
X. Benoit-Gonin,	IMFT
J.F. Alquier,	IMFT
E. Cid,	IMFT
S. Cazin,	IMFT
G. Barbut,	IMFT
R. Bourguet,	IMFT
R. El Akoury,	IMFT
G. Martinat,	IMFT
M. Liatsou,	HELIOTOPOS iutam2007@heliotopos.net
A. Papageorgiou,	HELIOTOPOS iutam2007@heliotopos.net
N. Rapti,	HELIOTOPOS iutam2007@heliotopos.net
K. Georgiou,	NTUA
G. Tzabiras,	NTUA
A. Zervos,	NTUA

General Services contributing to the Symposium

The symposium benefits from the general services of IMFT: Network and computing systems, (G. Martin), Signal-Image Processing (J.F. Alquier), Reprographics (M. Sabater), Numerical software (A. Stoukov), Administration (D. Barrau, C. Chupin and D. Bourrel) and Accounting services of ENSEEIHT, INPT and CNRS.

To the web site of the symposium contribute Y. Exposito and G. Martin, (IMFT), Y. Hoarau (Institut de Mécanique des Fluides et de Solides, Univ. Strasbourg).

We are grateful to these services for their continuous assistance to this symposium.