A new model for the cross spectrum and wavenumber-frequency spectrum of turbulent pressure fluctuations in a boundary layer

A model is developed for the statistical characteristics of the turbulent pressure field in a boundary layer. It is shown that the coherence scales are limited at low frequencies by the finiteness of the boundary layer thickness and at high frequencies by the effect of viscous forces acting in the flow. A relationship between the behavior of the coherence scales and that of the power spectra is demonstrated. The model is characterized by convertibility, which allows changes from cross spectra to wavenumber-frequency spectra and back via Fourier transformations. Calculations performed using the proposed model agree well with experimental results.