Wall-Pressure Spectral Model Including the Adverse Pressure Gradient Effects

摘要

An empirical model to predict the wall-pressure fluctuation spectra beneath adverse pressure gradient flows is presented. It is based on Goody's model, which already incorporates the effect of Reynolds number but is limited to zero pressure gradient flows. The extension relies on six test cases from five experimental or numerical studies covering a large range of Reynolds number, 5.6 × 10~2 < R_θ < 1.72 × 10~4, in both internal (channel) and external (airfoil) flows. A review of the boundary-layer parameters characterizing the pressure gradient effects is provided, and the more relevant ones are introduced as new variables in the model. The method is then compared to the zero pressure gradient model it is derived from. The influence of the pressure gradient on the wall-pressure spectrum is discussed. Finally, the method is applied to provide input data of a radiated trailing-edge noise model by means of an aeroacoustic analogy, namely Amiet's theory of turbulent boundary layer past a trailing edge. The results are compared to experimental data obtained in an open-jet anechoic wind tunnel.