Calibration of the Flow in the Test Section of the Low-Speed Wind Tunnel at AMRL
Abstract
The circuit of the low-speed wind tunnel remained essentially the same from when the tunnel was built in 1941 until 1996 when an extended test section and a new contraction were installed. In this report, the results of a detailed calibration of the flow in the test section are given for the tunnel with the contraction as installed from 1941 to 1996. The calibration was performed to: (1) provide a data base of the flow quality, to be used when analysing tests carried out between 1941 and 1996, and (2) provide a data base for assessing the changes in the flow quality resulting from the new contraction and extended test section installed in 1996. Longitudinal mean-flow velocities, flow angles, turbulence intensities and spectra, were measured at up to 155 grid points across the flow for longitudinal positions of X(sub T) = -1.0,0.0 and 1.0 m from the centre of the turntables in the test section for nominal free-stream velocities of 30, 45, 60 and 75 m/s. The most important area of the test section, where models are usually located, is the region comprising approximately the central 50% of the cross sectional area of the test section. In this region, over the longitudinal measurement range (X(sub T) -1.0 to 1.0 m), the following flow non-uniformities were observed. For the four velocities, longitudinal mean-flow velocities deviated within the range -0.8% to +2.0% from their values at the centre of the tunnel test section (X(sub T) = 0.0 m). For velocities of 30 and 60 m/s, horizontal flow angles deviated within the range 0.8 deg to +0.8 deg and vertical flow angles deviated within the range 1.0 deg to +0.4 deg. For velocities of 30 and 60 m/s, the u-component turbulence intensities were generally below 0.4%, and the v- and w-component intensities were generally below 0.7%.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2001
- Accession Number
- ADA397771
Entities
People
- Lincoln P. Erm