Author:
Christophe Julien,de Decker Julien,Schram Christophe
Abstract
AbstractWith the growth of modern turbofan engines, their integration under the wing becomes challenging and induces aerodynamic and acoustic interactions between the jet exhaust and the airframe. Jet noise reduction techniques have been widely studied over the past decades but their efficiency has still to be demonstrated once installed. The present lab-scale jet experiments at Mach 0.6 compare the noise radiated by beveled and rectangular installed nozzles to circular ones on a quarter-sphere radiation map using a microphone antenna. For all radiation angles, modified nozzles show an amplitude decrease of the jet-plate interaction tones of the noise spectra attributed to a strong coupling between the jet shear layers and the sound scattering at the plate trailing edge. Beveled nozzles achieve a noise reduction for all radiation angles with a maximum decrease up to 2 dB at receiver locations perpendicular to the plate. While rectangular nozzles show a similar behavior, a sound increase is observed for listeners parallel to the plate when the height-to-width ratio is small.
Publisher
Springer Science and Business Media LLC
Reference51 articles.
1. Ahuja, K.: An evaluation of various concepts of reducing supersonic jet noise. In: 13th Aeroacoustics Conference. American Institute of Aeronautics and Astronautics, Tallahassee, FL, USA (1990). https://doi.org/10.2514/6.1990-3982. https://arc.aiaa.org/doi/10.2514/6.1990-3982. Accessed 04 Mar 2023
2. Arndt, R.E.A., Long, D.F., Glauser, M.N.: The proper orthogonal decomposition of pressure fluctuations surrounding a turbulent jet. J. Fluid Mech. 340, 1–33 (1997). https://doi.org/10.1017/S0022112097005089
3. Bailly, C., Bogey, C., Castelain, T.: Subsonic and supersonic jet mixing noise. In: Measurement, Simulation and Control of Subsonic and Supersonic Jet Noise. von Karman Lecture Series (2016)
4. Bastos, L.P., Deschamps, C.J., da Silva, A.R.: Experimental investigation of the far-field noise due to jet-surface interaction combined with a chevron nozzle. Appl. Acoust. 127, 240–249 (2017). https://doi.org/10.1016/j.apacoust.2017.06.008
5. Brès, G.A., Jordan, P., Jaunet, V., Le Rallic, M., Cavalieri, A.V.G., Towne, A., Lele, S.K., Colonius, T., Schmidt, O.T.: Importance of the nozzle-exit boundary-layer state in subsonic turbulent jets. J. Fluid Mech. 851, 83–124 (2018). https://doi.org/10.1017/jfm.2018.476