A particle image velocimetry (PIV) investigation of a scramjet combustor with a cavity
flameholder is described. The first phase of planned research will apply two-dimensional PIV to
a measurement plane within the cavity flameholder and parallel to the flowpath central axis. The
resulting data are expected to reveal the interaction of cavity flow structures with the shear layer
separating the cavity and main-duct flows. Additionally, recirculation regions within the cavity
will be quantified. A second phase of the investigation will provide a cross-sectional view of the
combustor velocity field by applying three-dimensional PIV to measurement planes
perpendicular to the flowpath central axis. These data will be compared with results from
different experimental diagnostics developed by partner institutions. Preparations to date have
included the design of new hardware to accommodate unique requirements of this research
campaign, and testing is expected to begin in the spring of this year.