Abstract

A Trailing Edge Noise Metric has been developed for constructing response surfaces that may be used for optimization problems involving aerodynamic noise from a clean wing. The modeling approach includes a modified version of a theoretical trailing edge noise prediction and utilizes a high fidelity CFD (RANS) code with a two-equation turbulence model to obtain the characteristic velocity and length scales used in the noise model. The noise metric is not the absolute value of the noise intensity, but an accurate relative noise measure as shown in the validation studies. Parametric studies were performed to investigate the effect of the wing geometry and the lift coefficient on the noise metric. 2-D parametric studies were done using two subsonic (NACA0012 and NACA0009) and two supercritical (SC(2)-0710 and SC(2)-0714) airfoils. The EET Wing (a generic conventional transport wing) was used for the 3-D study. With NACA 0012 and NACA 0009 airfoils, a reduction in the trailing edge noise was obtained by decreasing the lift coefficient and the thickness ratio, while increasing the chord length to keep the same lift at a constant speed. Supercritical airfoil studies showed that decreasing the thickness ratio may increase the noise at high lift coefficients while a reduction may be obtained at low lift coefficients. Both 2-D and 3-D studies demonstrated that the trailing edge noise remains almost constant at low lift coefficients and gets larger at high lift coefficients. The increase in the noise metric can be dramatic when there is significant flow separation. Three-dimensional effects observed in the EET Wing case indicate the importance of calculating the noise metric with a characteristic velocity and length scale that vary along the span.

Meeting Name

42nd AIAA Aerospace Sciences Meeting and Exhibit (2004: Jan. 5-8, Reno, NV)

Department(s)

Mechanical and Aerospace Engineering

Sponsor(s)

Langley Research Center

Keywords and Phrases

EET Wing; Trailing Edge Noise Metric

Library of Congress Subject Headings

Aerofoils

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2004 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

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