The low turbulence wind tunnel (A3) is a closed section wind tunnel and is designed to provide a highly uniform and low turbulence flow. The A3 wind tunnel was designed and built by Dr R. V. Barrett* in the 1980s and has since been heavily used for fundamental and industrial applications. The test section has an octagonal shape with a cross-sectional area of about 0.8 m x 0.6 m and length of 1.6 m. The flow can reach a speed of up to 100 m/s in the test section. Thanks to its unique design, the flow is highly uniform in the test section, with a very low turbulence intensity of 0.05%. The wind tunnel is equipped with a 3-axis overhead ATI force balance system, Laser flow diagnostics including Laser Doppler Anemometry and several Particle Image Velocimetry systems (conventional and time-resolved Dantec 2D planar, stereoscopic and LaVision tomographic PIV) and Constant Temperature Hotwire Anemometry systems. The facility is currently used for a range of applications, including aerodynamics of airfoils, fundamental turbulence, flow control, bluff bodies, low-drag surfaces, birds aerodynamics, etc.

*Barrett, R. V. "Design and performance of a new low turbulence wind tunnel at Bristol University." The Aeronautical Journal 88.873 (1984): 86-90.