Grazing flow tube
There are two flow tube facilities in AANTC to study the effects of grazing flows on acoustic liners. Impedance eduction methods are conducted for different types of sound absorption materials. The dimensions of tubes are 50x50 mm and the working frequency is 400-3400 Hz. The maximum Mach and sound pressure levels for a are 0.1 and 120 dB, respectively. The test rig is upgraded to enable wide test range. The Mach number ad SPL limits are 0.3 and 140 dB, respectively. More details: Wei Yi, et al., Acoustic impedance measurements using an advanced grazing flow tube facility, 28th International Congress on Sound and Vibration, 2022.