Affiliations: Graduate Research Assistant, Department of Mechanical
Engineering, Florida A University and Florida State University, Tallahassee,
Florida 32310, USA | Professor, Department of Mechanical Engineering,
Florida A University and Florida State University, Tallahassee, Florida
32310, USA | Professor and Chair, Department of Mechanical
Engineering, Florida A University and Florida State University, Tallahassee,
Florida 32310, USA
Abstract: The effect of acoustic feed back on global flow response is
illustrated through an example of a rectangular screeching jet operating at a
nominal Mach number of 1.69. Using a stereoscopic Particle Image Velocimetry,
the detailed flow characteristics within a screeching cycle are obtained with
fidelity. To resolve the "bias" errors inherent with standard PIV image
processing technique, a novel mesh-free and high spatial resolution scheme is
implemented to yield accurate velocity measurements in a complex
three-dimensional supersonic flow. The axis-switching phenomenon that arises
due to unusual mixing enhancement in the minor axis plane of a rectangular jet
is vividly displayed. Strong streamwise vortex structure in the jet shear
layers, enhanced by the inherent instability of the shear layer, is
reported.
