Particle Image Velocimetry in an Isothermal and Exothermic High Speed Cavity (Postprint)
Abstract
Particle image velocimetry measurements were taken at the center plane of a high-speed cavity combustor in isothermal and reacting conditions at fuel flows corresponding to medium, medium-high, and high power conditions with supersonic bulk flow velocities. Calculation of the instantaneous and time-averaged particle traces, vorticity, principal stresses, and divergence of the velocity field revealed a highly unsteady, three-dimensional flow with coherent eddy structures formed at the stagnation zone of the shear layer against the downstream ramp of the cavity that appear to be convected upstream in the cavity. Comparison of the shear layer location, thickness, and reattachment stagnation point revealed a number of changes in the mean and unsteady velocity behavior that were dependent on the heat release in the cavity and shear layer. As combustion shifted from the cavity at medium power into the shear layer at high power, the volumetric expansion compressed the primary recirculation zone and thickened the downstream boundary layer at the cavity exit. Combustion in the cavity tended to attenuate cavity and shear layer unsteadiness. When the combustion shifted to the shear layer, velocity unsteadiness increased, though not to the amplitudes measured without combustion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2012
- Accession Number
- ADA558957
Entities
People
- Campbell D. Carter
- Kuang-yu Hsu
- Steven G. Tuttle
Organizations
- Air Force Research Laboratory