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COBEM 2017
24th ABCM International Congress of Mechanical Engineering
PREDICTION OF SOUND PROPAGATION EFFECTS OF INSTALLED JET CONFIGURATIONS AT SUBSONIC OPERATING CONDITIONS
Submission Author:
Rodrigo Godoy da Fonseca , PA
Co-Authors:
Rodrigo Godoy da Fonseca, Thiago Henrique Gomes Lobato, Gustavo da Silva Vieira de Melo, Leopoldo Bastos, Carlos Roberto Ilário da Silva
Presenter: Thiago Henrique Gomes Lobato
doi://10.26678/ABCM.COBEM2017.COB17-1924
Abstract
Aircraft noise is associated to noise pollution and various adverse effects on human health, thus representing an important barrier to the growth of aviation transport system. In this regard, developing numerical tools with improved predictive capabilities is crucial for noise reduction solutions. In this regard, the present work accounts for the development and evaluation of a sound propagation numerical model based on two-dimensional Ray-tracing method, which is able to predict major installation effects. These effects are inherent to under-wing-mounted engine configurations, originating from interaction between sound sources of exhausting jet and solid surfaces, such as wing and flap. This is accomplished by combining the fundamental Ray-Tracing equations with a sound reflection algorithm. The flow domain properties required to the numerical model, are previously calculated via Computational Fluid Dynamics (CFD) based on Reynolds Averaged Navier-Stokes (RANS). Acoustic rays, representing the sound energy of the flow sources, are launched from point sources, distributed throughout the jet, and their propagation paths are obtained by solving the Eikonal equation. The numerical tool was evaluated through qualitative analyses of the ray paths considering different flow conditions and wing-flap configurations. Based on the results, it was observed that the implementation of the new predictive capabilities substantially modified the behavior of the acoustic rays, resulting in more realistic propagation paths.
Keywords
jet noise, installation effects, Ray-tracing, Computational Fluid Dynamics, Eikonal equation
