title: Scattering of turbulent-jet wavepackets by a swept trailing edge.
abstract: Installed jet noise is studied by means of a simplified configuration comprising a flat plate in the vicinity of a round jet. The effects of Mach number, jet-plate radial distance, and trailing-edge sweep angle are explored. Acoustic measurements are performed using a traversable 18-microphone azimuthal array, providing pressure data at 360 points on a cylindrical surface surrounding the jet-plate system. Key observations include a decrease, with increasing Mach number, of the relative level of the scattered field in comparison to the uninstalled jet; an exponential dependence of the scattered sound pressure level on the radial jet-plate separation; and considerable sideline noise reductions with increasing sweep angle, with which there is an overall reduction in acoustic efficiency. The measurements are compared with results obtained using a kinematic wavepacket source model, whose radiation is computed in two ways. A TGF for a semi-infinite flat plate is used to provide a low-order approximation of the scattering effect. Use of a more computationally intensive boundary element method provides additional precision. Good agreement between model predictions and experiment, encouraging from the perspective of low-cost prediction strategies, demonstrates that the models comprise the essential sound generation mechanisms.
authors.affiliation: Institute Pprime, 43 rue de l'Aérodrome, 86036 Poitiers, France.
authors.forename: Selene
authors.initials: S
authors.lastname: Piantanida
authors.affiliation: Institute Pprime, 43 rue de l'Aérodrome, 86036 Poitiers, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jaunet
authors.affiliation: Acoustic Department, Airbus Operations, 316 route de Bayonne, 31060 Toulouse, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Huber
authors.affiliation: Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica, Departamento de Energia, Rua Mendeleyev, 200, Unicamp, 13083-970, Campinas - SP, Brazil.
authors.forename: William R
authors.initials: WR
authors.lastname: Wolf
authors.affiliation: Institute Pprime, 43 rue de l'Aérodrome, 86036 Poitiers, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Jordan
authors.affiliation: Instituto Tecnológico, Divisão de Engenharia Aeronáutica, Praça Mal. Eduardo Gomes, 50, Vila da Acácias, 12228-900, São José dos Campos - SP, Brazil.
authors.forename: André V G
authors.initials: AV
authors.lastname: Cavalieri