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The broadband noise generated by the scattering of turbulent flow at the trailing edge of a NACA 0018 airfoil with trailing edge serrations is investigated varying both the airfoil angle of attack and serration flap angle. Acoustic emissions from the trailing edge are measured using a microphone array. The noise level

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The trailing edge of a NACA 0018 airfoil is modified through the attachment of serrations with different degrees of permeability. Acoustic beamforming is used to inspect the turbulent boundary layer-trailing edge noise emissions from the unmodified and serrated trailing edges. Different freestream velocities and angles of attack are investigated. The serration permeability is prescribed by having slits cut into the solid surface of the serrations in two different configurations. The results indicate that a certain benefit in noise reduction is obtained from a mixed solid/slitted configuration, while a fully slitted configuration loses most of the noise reduction performance.

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