Walker discusses separated flows at conference in France

J. D. A. Walker, professor of mechanical engineering and mechanics, gave
an invited keynote address to a IUTAM (International Union of
Theoretical and Applied Mechanics) conference on Unsteady Separated
Flows held recently in Toulouse, France. Walker’s talk titled “Unsteady
separation processes at high Reynolds number and their control,”
discussed how boundary-layer separation from the leading edge of
airfoils and helicopter blades at low Mach numbers can be inhibited,
thereby suggesting new designs for more maneuverable rotorcraft.
Walker’s work is supported through the U.S. Army Research Office.

Walker gave a second invited keynote talk on “Supersonic boundary-layer
separation and the influence of a compliant surface,” which concerned
situations where pockets of reversed flow develop near a surface in
high-speed compressible flow. Such regions of recirculating flow exhibit
strong instabilities that can provoke a premature transition to
turbulence. Walker described the conditions under which such phenomena
occur and how the instabilities can be suppressed by using a properly
designed flexible surface on supersonic aircraft surfaces.