Objectives of the Workshop

In recent years much progress has been made in the area of transition from laminar flow to turbulence in external flows, in particular for boundary layers. These results are beginning to find their way in other areas such as internal flows which do not exhibit a linear instability scenario. Examples are: the Couette and the cylindrical Poiseuille flow. In addition some new experimental and numerical material on these flow have been reported recently in the literature. Therefore, the time seems ripe to review these results and to decide which roads are most probably to lead to further results.

The goals for this workshop that are mentioned above, seem to be served best when we keep this workshop somewhat limited in attendance and encourage both experts in this area to attend and Ph.D. students who are presently involved in research on this topic.

---

Discussion Groups and Presentations

Apart from presentations of research we had the idea that we should honor the name "work shop" and do some real work. For this we have the intention of setting up three discussion groups which will meet on the wednesday and thursday afternoon for about one hour and a half during which they should formulate a point of view on a particular topic in transition. On Friday morning at the end of the meeting we will then organize a plenary discussion with everybody and discuss the topics which have been prepared in the three discussion groups. We also plan to publish the results of these discussions in the Ercoftac bulletin as outcome of the workshop.

The following discussion groups will be formed and the discussions will be lead by the mentioned chairmen.

1. Theoretical nonlinear developments in deep transition: Frank Smith
2. The role of transients and non-normal effects in transition to turbulence: Dan Henningson
3. Engineering problems related to transition: Anatoli Tumin

To make the discussion as usefull as possible to it's participants, we hope that you will decide on forehand which group you want to join and mail your choice to Cas van Doorne. We will then add your name to the discussion group and advertise it on this page. If you would like to suggest some topics for discussion and maybe some material (papers) to study, we might advertise it as well.

We hope that your effort will be rewarded with very intresting and useful discusions.

Participants

Prof. Y.S. Kachanov has been invited to give the first lecture. The title of his presentation is "Nonlinear mechanisms of transition".

List of particpants and presentations:

Dr. P. Henrik Alfredsson
"Sub-critical transition and streaky structures."

Anatoli Tumin
"Late stages of transition in Poisseuille pipe flow."

Olivier Dauchot
"coherent structures in the subcritical transition to turbulence: from plane to cylindrical Couette flow."

Prof. L. N. Trefethen, Oxford University Computing Laboratory
"New results by Jon Chapman on transition in channels."

Dr. A. Meseguer, Oxford University Computing Laboratory
"A Petrov-Galerkin spectral code for pipe flow."

Renzo Piva
"Formation of turbulence spots from localyzed perturbations in Poisseuille flow."

Dan Henningson, KTH/FFA
"Transients and non-normal effects in channel flow and boundary layer transition."

Stellan Berlin, Parallel Systems
"Flow structures in the late stages of O, H and K -type transition."

Luca Brandt, KTH
"Secondary instability of streaks in boundary layers."

Frank T. Smith
"Spiking theory: internal versus boundary layers."

Robert Bowles
".."

B. Eckhardt
"Transition to turbulence in plane shear flow."

Armin Schmiegel
"Stationary states in plane Couette flow."

Holger Faisst
"Transition from the Couette-Taylor system to the plane Couette system."

Jorg Reuter
"Numerical investigations into the stability of longitudinal vortices in pipe flow"