On the Modeling of Wall Surface Pressure Spectra for Trailing Edge Noise Prediction

Abstract

Broadband noise is a significant source for open rotors and Ultra High Bypass Ratio fans. The analytical description of the leading edge noise component is typically linked to the upwash velocity autospectrum of the impinging turbulence, and the modeling of the trailing edge component due to the interaction of the boundary layer turbulence with the trailing edge relies on the surface pressure autospectrum near the trailing edge. But while there is some consensus on describing transverse velocity frequency spectra for leading edge noise, there are a plethora of different models of varying complexity to describe wall surface pressure autospectra. Choosing an appropriate model to apply in the framework of fast and robust acoustic prediction tools is therefore no easy task. This paper aims to apply different models for predicting the surface pressure spectrum near the trailing edge of an airfoil. Experimental data for two airfoils at realistic flight Mach and Reynolds numbers were studied and different RANSinformed empirical models as well as the Stalnov TNO model were investigated regarding their ability to capture experimental trends.