Type: Seminar

Distribution: World

Expiry: 24 Sep 2008

Auth: wm@p6283.pc.maths.usyd.edu.au

This talk will present some new results on an old problem of (very) short-scale instabilities in boundary-layer flows. Starting with a rather simple flow over a heated surface we can show that the boundary-layer equations predict an anomalous short scale instability that is independent of the Reynolds number, a non-dimensional parameter that defines the dynamics of our fluid system. The origin of this short scale instability is explored and shown to be linked to a finite distance singularity which arises in the boundary-layer equations. We’ll then go on to show that this singularity occurs in a wide range of boundary-layer problems and attempt (but perhaps fail) to argue that it is non-physical by presenting some calculations from a full numerical solution of the Navier-Stokes equations. http://www.maths.usyd.edu.au/u/AppliedSeminar/abstracts/2008/denier.html