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Impact of cavity edges shape on aerodynamic noise

Łojek Paweł, Czajka Ireneusz

Vibrations in Physical Systems

2022

Vol. 33, nr 3

art. no. 2022301

In this article, the analysis of influence of cavity edge shapes on flow-generated noise is performed. The acoustic wave propagation in the channel, that result from the flow, was analyzed. Shape of upstream and downstream edges was modified. The hybrid method based on Navier-Stokes and Perturbed Convective Wave Equation was used to solve the unidirectional coupling. The research showed a significant influence of the modification of the shape of the cavity edges on the generated noise. The change of downstream corner allowed for significant reduction of noise in the entire analysed band and allowed for the reduction of overall sound pressure level (OASPL) by 5 dB. Modifications of the upstream edge did not bring such differences, change in OASPL was up to 1 dB. The obtained spectra of the sound pressure level showed compliance with the calculated natural frequencies of the analysed object, as well as with some of the Rossiter modal frequencies, typical for the phenomena occurring in the cavities.

Influence of the elastic cavity walls on cavity flow noise

Łojek Paweł, Czajka Ireneusz, Gołaś Andrzej, Suder-Dębska Katarzyna

Vibrations in Physical Systems

2021

Vol. 32, nr 1

art. no. 2021109

In this study, computational fluid dynamics and computational aeroacoustics methods were used to investigate the influence of the elastic cavity walls on the noise generated by the flow over rectangular cavity. Two cases were considered and compared, one with rigid cavity walls, and one with elastic walls. In the latter case, the movement of the walls were solved by finite element modelling and coupled with CFD simulations. The noise generated by the flow over cavity was computed using Ffowcs Williams & Hawkings acoustic analogy. The increase of the sound pressure level for elastic walls case at frequency range of 1 kHz to 10 kHz is observed, compared to the rigid walls case.

Influence of cavity edges shape on flow induced noise

Łojek Paweł, Suder-Dębska Katarzyna, Mach Michał

Vibrations in Physical Systems

2021

Vol. 32, nr 1

art. no. 2021110

In this paper, impact of the cavity shape on flow-generated noise is analysed. As reference model, the classic rectangular cavity with perpendicular corners was used. The impact of both upstream and downstream edges was analyzed. In this paper, authors used hybrid method, where the flow was computed by means of Spalart-Allmaras Detached Eddy Simulations (DES) model, and the acoustic wave propagation was calculated by Curle acoustic analogy.