Direct Simulation of flow-acoustics feedback phenomena for ducted diaphragm tandem using OpenFOAM
Résumé
The proximity of obstacles in ventilation or climate control systems present in different industries (automotive, aeronautics, rail) can result in a significant increase of the noise production due to retroactive effects of the acoustic waves generated by the turbulent flow on the flow itself and can be a serious problem for the design of such systems. In this study, the noise resulting from a tandem diaphragm configuration in a rectangular duct is investigated: the disturbed flow that reaches the second obstacle is shown to yield acoustic feedback. Explanations and illustrations of this aeroacoustic phenomenon (structures shedding, tonal components) are given from the results of a direct noise prediction using OpenFOAM compressible solver. Those numerical results are also compared with experimental data.