Acoustic analysis of flat plate trailing edge noise

Abstract

This paper presents an acoustic analysis of the noise generated at the trailing edge of a flat plate encountering low turbulence fluid flow. Experimental measurements were taken in an anechoic wind tunnel using four microphones: one mounted above the trailing edge, one below the trailing edge, one adjacent to the trailing edge and one above the leading edge. The noise spectra produced by the flat plate were recorded at the four microphone locations. Information about the strength and directivity of the trailing edge noise is determined by comparing the four signals. Subtracting the out-of-phase signals at the microphones above and below the trailing edge is shown to increase the airfoil self-noise spectra further above that of the ambient noise and is shown to be an effective signal extraction technique.