Turbulent boundary layer trailing edge noise is the dominant noise in airfoil self-noise. This noise generated by the trailing edge can be minimized by different edge treatments. Varying the acoustic impedance of the trailing edge acoustic radiation can be varied. A NACA0012 symmetric airfoil with 0.3 mm thick solid and perforated plate fitted at the trailing edge is used for this study. Experiments were carried out in an anechoic facility at different velocity varying from 20 to 45 m/s and geometric angles of attack of 0o. Solid trailing edge extension and perforated trailing edge extensions enhance the noise reduction in the low frequency range. As compared to solid extensions perforated extensions provide greater noise reduction. Maximum noise reduction of approximate 6.5 dB in the low frequency range is obtained for the perforate plate attachment at zero angle of attack. At higher velocities an increase in the high frequency noise is observed due to the roughness offered by the perforated extension plate. OASPL analysis shows the strong dependency of the trailing edge with the jet velocity.
