Acoustic field around a transonic cavity flow. Issue 6 (September 2017)

• Record Type: Journal Article
• Authors: Loupy, GJM; Barakos, GN; Kusyumov, A
• Is Part Of: International journal of aeroacoustics. Volume 16:Issue 6(2017)
• Page Start: 507
• Page End: 535
• Publication Date: 2017-09
• Subjects: Cavity flow -- ransonic -- beamforming -- modelling; Aerodynamic noise -- Periodicals; Acoustical engineering -- Periodicals; Sound -- Periodicals; 629.1323
• DOI: 10.1177/1475472X17730459
• Languages: English
• ISSNs: 2048-4003

Abstract

This paper describes new techniques for analysing cavity flows. The beamforming method is used to estimate the pressure fluctuations inside a resonant transonic cavity, highlighting the localisation of the sources of noise. The method produces insightful results and only requires the use of an acoustic array and a mean flow-field. The technique models the noise propagation in a simple and efficient way, applicable for wind tunnel test. In addition, this paper discusses the generation of the cavity tones. Computational fluid dynamics results are analysed using a superposition of reflected acoustic waves driven by the cavity flow. This analysis shows that the time-averaged flow-field drives the frequencies of the tones, while the flow-field fluctuations drive their amplitude. In addition, the tonal dynamics of the cavity flow are represented by a simple model with standing wave oscillations and their modulation. This work is complementary to the well-established Rossiter cavity model.