Calibration of the Flow in the Test Section of the Research Wind Tunnel at DST Group
DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION FISHERMANS BEND (AUSTRALIA) FISHERMANS BEND Australia
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Results are given of a detailed calibration of the flow in the test section of the Research Wind Tunnel at DST Group. The calibration was performed to establish the flow quality and to provide guidance when determining the suitability of the tunnel for given tests. Longitudinal mean-flow velocities, flow angles and longitudinal-component turbulence intensities were measured at up to 187 grid locations across the flow at the centre of the test section for nominal free-stream velocities of 10 and 20 ms-1. Measurements were taken when screens were installed in the tunnel and when there were no screens in the tunnel. 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, the following flow non-uniformities were observed when screens were in the tunnel. For nominal free-stream velocities of 10 and 20 ms-1, velocity deviations varied by about 0.5, horizontal and vertical flow angles varied by about 0.6, and longitudinal-component turbulence intensities were below about 0.3. The variations in flow parameters are comparable with acceptable variations quoted in the literature. Based on these measurements, the tunnel is considered suitable for flow-visualization studies around models and the measurement of forces, moments and pressures on models. The tunnel may not be suitable for boundary-layer-transition studies, due to the moderate levels of free-stream turbulence levels in the tunnel. Possible ways of modifying the tunnel to improve the flow in the test section are suggested.
- Test Facilities, Equipment and Methods