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AIAA JOURNAL

Pages:

pp 11

Volume:

48

Issue:

9

Date:

Wednesday, September 1, 2010

DOI:

http://dx.doi.org/10.2514/1.J050206

A method is proposed to calculate the trailing-edge broadband noise emitted from an airfoil, based on a steady

Reynolds-averaged Navier–Stokes solution of the flowfield. For this purpose, the pressure spectrum on the airfoil

surface near the trailing edge is calculated using a statistical model from the Reynolds-averaged Navier–Stokes mean

velocity and turbulence data in the airfoil boundary layer. The obtained wall-pressure spectrum is used to compute

the radiated sound by means of an aeroacoustic analogy, namely, Amiet’s theory of airfoil sound. The statistical

model for wall-pressure fluctuations is validated with two test cases from the literature, a boundary layer with an

adverse pressure gradient, and a flat plate boundary layer without a pressure gradient. The influence of specific

model assumptions is studied, such as the convection velocity of pressure-producing structures and the scale

anisotropy of boundary-layer turbulence. Furthermore, the influence of the Reynolds-averaged Navier–Stokes

simulation on the calculated spectra is investigated using three different turbulence models. The method is finally

applied to the case of a Valeo controlled-diffusion airfoil placed in a jet wind tunnel in the anechoic facility of École

Centrale de Lyon. Reynolds-averaged Navier–Stokes solutions for this test case are computed with different

turbulence models, the wall-pressure spectrum near the trailing edge is calculated using the statistical model, and the

radiated noise is computed with Amiet’s theory. All intermediate results of the method are compared with

experimental data.

Rights:

2010 by the authors

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