Aeroacoustic
University of Bristol
The aeroacoustic wind tunnel at the University of Bristol consists of a very quiet closed-circuit wind tunnel and a large anechoic chamber*. The Wind tunnel is powered by a 75kW centrifugal fan and is equipped with a series of large silencers to reduce the fan noise in the ductwork. The wind tunnel is equipped with a 40kW water cooled chiller, enabling continuous testing at a set temperature, between 15o to 30o. The anechoic chamber is approximately 7m x 4.5m x 3.5m and is fully anechoic down to 160Hz. Several contraction nozzles with different aspect- and contraction-ratios, including nozzles with exit cross-sectional areas of 500mm (W) x 775mm (H), 400mm (W) x 600mm (H) and 600mm (W) x 200mm (H), have been made for measurement of aerodynamic and aeroacoustic performance of different aero-components, such as aerofoils, bluff bodies, boundary layer, etc. A free-stream velocity range from 8m/s to 120m/s can be achieved with very low free-stream turbulence intensity of approximately 0.1% at 30m/s.
The working section of the tunnel is extended with a Kevlar-wall test section can for examining static and dynamic aerofoil noise at large angles of attack. In terms of measurement capabilities, the wind tunnel is equipped with three Dantec hotwire CTA system (6 channels), 2D PIV, several pressure scanners, hotfilm CTA system (80 channels), two source location beamforming arrays (a circular and an elliptic array with 73 and 83 free-field microphones, respectively ), an far-field arc of over 50 GRAS and B&K free-field microphones for far-field noise measurements, and large number of in-house designed and fabricated unsteady pressure transducers (over 120), suitable for surface pressure fluctuation measurements. Four National Instrument DAQ are used in the aeroacoustics facility, enabling simultaneous data collection of up to 160 channels for simultaneous dynamic surface pressure and coupled pressure-velocity measurements.
The facility was designed by Professor Mahdi Azarpeyvand.
- Location:
- Bristol
- Test Section 1 size:
- Anechoic chamber: approximately 7 x 4.5 x 3.5m
High-Speed nozzle: 0.6 x 0.2m maximum speed 100m/s
Medium-Speed nozzle: 0.6 m x 0.4 m; maximum speed 60m/s
Low-Speed nozzle: 0.6 m x 0.755 m; maximum speed 40m/s
Jet: 1.5inch diameter; maximum speed 1.4 Mach
- Operational Status:
- Active
- Number and Type of Staff:
- Scientific: 6
Technical Support: 4
- Test support:
- Workshop for wind tunnel model design, manufacture and modification capability.
- Designation:
- Low Speed, Aeroacoustic
- Performance:
-
Mach Number: Jet: 1.4 Mach
Maximum Flow Speed: Low speed nozzle: 40m/s
Medium speed nozzle: 60m/s
High speed nozzle: 80m/s
Jet:1.4Mach
Turbulence intensity: <0.1%
- Testing Capabilities:
-
Outputs: Acoustic: Near-field and far-field
Aerodynamic loads: Force plates, force cubes, load cells, etc
Laser Measurements: TR-PIV
Flow visualisation: Hotwire, hotfilm
- Specialist Rigs:
- • Source location microphone array (73 microphones)
• Source location microphone array (83 microphones)
• Mems-based microphone array (124 microphones)
• Array of over 80 GRAS and B&K free-field microphones for far-field noise measurements
• Several single-rotor and multi-rotor propeller systems
• Several highly instrumented airfoils, and high-lift devices, cylinders, jet nozzles, etc.
- Equipment:
- Three Dantec hotwire CTA system (6 channels)
2D PIV, TR-PIV, pressure scanners, load cells,
Hotfilm CTA system (80 channels)
Source location microphone array (73 microphones)
Source location microphone array (83 microphones)
Mems-based microphone array (124 microphones)
Over 80 GRAS and B&K free-field microphones for far-field noise measurements
Several Kulite pressure transducers
Large number of in-house designed and fabricated unsteady pressure transducers (over 250), suitable for surface pressure fluctuation measurements
Four National Instrument DAQ systems, enabling simultaneous data collection of up to 160 channels
Several highly instrumented airfoils, and high-lift devices, cylinders, jet nozzles, etc.