25-10-2012, 05:38 PM
Shear Layer Dynamics in Resonating Cavity Flows
ABSTRACT
The shear layer above open cavities were studied through detailed velocity and surface pressure measurements sampled
in a synchronous manner. The Particle Image Velocimetry measurement yielded mean flow characteristics and instantaneous
flow snapshots. The mean turbulent quantities showed the dominance of the shear layer and the region around the corner of
the aft wall. Cross-correlations of the surface pressure measurements showed evidence of the shear layer structures being
convected downstream and an upstream propagating acoustic wave for the cases where resonance occurred. The PIV data was
also combined with the surface pressure measurements through the application of the Quadratic Stochastic Estimation
procedure to provide time resolved snapshots of the flow field. Examination of these results indicate the strong pumping action
of the cavity regardless of whether resonance existed and was used to visualize the large scale structures interacting with the
aft wall.