AEROACOUSTIC OF AIR DUCT ELEMENTS : NOISE REDUCTION OF EXTRACTION OUTLETS

摘要

This investigation acquired a database on the longitudinal space-time correlation, frequencyspectra and frequency cross-spectra of the wall pressure fluctuations beneath twoconfigurations of geometry. The results presented give little indication can be estimated fromstatistics properties as to the contribution of the wall pressure fluctuations, The evolution oflongitudinal r.m.s wall pressure as function of transducers position, reveal apparition of largeregion of turbulent separation. We have obtained an optimal inner shape of the configurationsthat permit to reduce noise radiated. It would be aimed to carry our attention on themodification of the field of fluctuation velocity inside wall define by different configurations,which are the possible sources of noise in the flow.