Final Flow Survey of Langley 12-ft Low Speed Tunnel

A dynamic pressure calibration was conducted in the NASA Langley 12-Foot Low-Speed Tunnel for the final year of its operation. The objective was to calibrate the wall-mounted pitot static probe, used to measure freestream dynamic pressure during normal tunnel operations, relative to the dynamic pressure recorded over a cross-sectional area of the test section. The survey provided a calibration factor to be applied to the wall probe to accurately reflect an area weighted average of the air flow through the test section. Heat maps were also generated to visually show areas of the test section that airflow differs from the wall probe reading. This paper details the survey probe rake used and the methods for generating a calibration value for the tunnel as well as the implementation of that value. This calibration value serves as a correction factor that any testing in the tunnel would apply to the recorded data.