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Description
Flow induced noise in piping systems can lead to unacceptable acoustic emissions, vibration, and long term structural damage. Identifying the physical mechanisms and spatial regions responsible for sound generation remains challenging, particularly in turbulent flows where convective pressure fluctuations coexist with radiating acoustic waves. In this work, a rectangular T-junction with a cavity, whistling under turbulent flow excitation is investigated. The whistling aeroacoustic instability results from the constructive interaction of the acoustic waves in the cavity and the turbulent shear layer. In the present study, we revisit a previously published dataset, combining Particle Image Velocimetry (PIV) and acoustic Multi-Microphone Method characterization to identify and localize aeroacoustic sources using vortex-sound theory. Howe’s acoustic analogy is applied to the resolved flow fields to compute the vortex sound source term, enabling the spatial localization of regions that contribute most strongly to acoustic radiation.In addition, an attempt at distinguish pseudo sound—convective, non-radiating pressure fluctuations—from true acoustic waves is made. Correlations between pressure signals, vorticity, and far-field acoustic observables are employed to separate hydrodynamic pressure components from propagating sound using the correlation between pressure signals measured at different locations.