Manchester Applied Mathematics and Numerical Analysis Seminars Winter 1999/2000

December 15, 1999, 2.30 pm

Lecture Theatre OF/B9 Oddfellows Hall (Material Science)

Instability in the Blasius boundary layer

Dr. J.J. Healey, Department of Mathematics, Keele University

Most of the drag on a streamlined body moving quickly through a fluid (like an aeroplane wing, or turbine blade) is due to the skin friction at the surface produced by the boundary layer. This depends greatly on whether the boundary layer is laminar or turbulent. Although much is now known about the transition from laminar to turbulent flow, aeronautical engineers still rely on empirical transition prediction methods, and direct numerical simulations of the equations of motion seem likely to remain unattainable for the forseeable future.

This work is concerned with developing a consistent high-Reynolds number theory for the weakly nonlinear-nonparallel evolution of disturbances in a boundary layer. Although the techniques for developing this theory have been available for some time, it is the use of symbolic manipulation packages that now enables us to attempt to develop a theory that is accurate enough at finite Reynolds numbers to be useful to engineers working on transition prediction. This talk will present results of work in progress that is moving towards this goal.

For further info contact either Matthias Heil (mheil@ma.man.ac.uk), Mark Muldoon (M.Muldoon@umist.ac.uk)or the seminar secretary (Tel. 0161 275 5800).