Laser-Raman/Rayleigh Flow Diagnostic Techniques Applied to Subsonic Flow.

The feasibility of performing laser-Raman/Rayleigh scattering measurements in subsonic flows was demonstrated in the 6-in. Acoustic Research Tunnel (ART) of the Propulsion Wind Tunnel facility at AEDC. The ART is an open-circuit, atmospheric inbleed tunnel that operates on the Plenum Evacuation System of the 16-ft transonic Propulsion Wind Tunnel (16T). Laser-Raman/Rayleigh scattering techniques were used to measure air number density, H2O number density, and static temperature and to detect the onset of water vapor condensation. Measurements were made near the tunnel axial centerline over the Mach number range from 0.10 to 0.80. Measurements were also made in the turbulent boundary layer on the wall of the test section at Mach numbers 0.50 to 0.80. (Author)
Prepared in cooperation with ARO, Inc., Tullahoma, TN.