Acoustic Wave Propagation Through Shear Layer of the German-Dutch Open Jet Wind Tunnel (DNW)

摘要

The acoustic correction procedures for 1/3 octave analysis in a 20 m long open jet, surrounded by a large anechoic room, were checked with a calibrated noise source using noise data taken inside and outside the flow. Multitone marine horns and an acoustic driver coupled to a horn for broadband and single tone noise were used. The usual instrumentation and wind tunnel corrections can be applied. The usual shear layer correction, based on an infinitely thin shear layer, has to be extended to correct for turbulence and other effects for the case of high tunnel velocity, high frequency, and the most forward and the most rearward propagation angles from the sound source. This correction is insensitive to the position of the model in the flow and type of sound source (tone or broadband).