Aeroacoustic measurement of 30P30N high-lift configuration in the test section with Kevlar cloth and perforated plate

Both aerodynamic and aeroacoustic measurements in wind tunnels are necessary for the study of high-lift devices. The existing wind tunnels have difficulties in simultaneously measuring aerodynamic features in a stable condition with less flow interference and aeroacoustic characteristics in a non-reflecting environment with good sound transmission. The test section in D5 aeroacoustic wind tunnel at Beihang University is recently upgraded for the aeroacoustic measurement of 30P30N high-lift configuration. The sidewall on the suction side consists of internal Kevlar cloth tensioned by a perforated plate and the other sidewall on the pressure side only consists of Kevlar cloth. Both aerodynamic and aeroacoustic features are measured to validate the performance of this test section. The surface static pressure distributions measured in D5 are similar to JAXA's results, verifying the similarity of flow field and the reliability of experiments. For acoustic field, noise spectral shape, tonal frequency and noise source location all agree well with aeroacoustic characteristics of high-lift configurations in previous investigations and numerical simulations. Thus, the test section overcomes the limitations and disadvantages of open and closed hard-wall test sections and can be applied for aerodynamic and aeroacoustic measurements of high-lift devices in aeroacoustic wind tunnels, especially for small scale wind tunnels.