Characterization of The Flow Quality in the Boeing Subsonic Wind Tunnel

Good wind-tunnel flow quality characteristics are vital to using test data in the aerodynamic design process. Spatially uniform velocity profiles are required to avoid yaw and roll moments that would not be present in real flight conditions. Low turbulence intensity levels are also important as several aerodynamic properties are functions of turbulence intensity. When measuring mean flow and turbulence properties, hot-wire anemometry offers good spatial resolution and high-frequency response with a fairly simple operation, and the ability to make near-wall measurements. Using hot-wire anemometry, flow quality experiments were conducted

in a closed-circuit wind tunnel with a test section that has a cross section area of 1.2 m x 1.8 m (4 ft. x 6 ft.). The experiments included measurements of flow velocity and turbulence intensity variation over the test section cross-section, spatial and temporal temperature variation, and

boundary layer measurements. The centerline velocity and turbulence intensity were also measured for flow speeds ranging from 13 to 43 m/s.