Investigations of Cavity Noise Generation on a Cylinder
Cavity noise generation is of particular interest for e.g. the aeronautical and automotive industry where a lot of different shaped cavities occur on curved surfaces. In this work the flow over a small rectangular cavity (L/D ≈ 1) on a cylinder at velocity ramps up to 45 m/s was investigated in an acoustic wind tunnel. Acoustical and PIV measurements indicate a sudden transition of the circulating flow to a turbulent boundary layer at the typical Reynolds number leading to cavity noise. The onset of the acoustic radiation is contemporaneous with this transition and shows a strong hysteresis. Pressure measurements directly on the cylinder surface reveal a hydrodynamics and acoustics coupling point in front of the cavity.
KeywordsWind Speed Particle Image Velocimetry Turbulent Boundary Layer Sound Pressure Level Sound Generation
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- 1.Rossiter, J.E.: Wind-tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Aero. Res. Counc. R&M, No. 3438 (1964)Google Scholar
- 2.Cattafesta, L., Williams, D., Rowley, C., Alvid, F.: Review of active control of flow-induced cavity resonance. AIAA 2003-3567 (2003)Google Scholar
- 3.Colonius, T.: An Overview of Simulation, Modeling, and Active Control of Flow/Acoustic Resonance in Open Cavities. AIAA 2001-0076 (2001)Google Scholar
- 4.Added in proof: New measurements revealed Kelvin-Helmholtz instabilities as the source for the observed frequencies. Details will be published in another paper soonGoogle Scholar