A PARAMETRIC STUDY ON WALL PRESSURE WAVENUMBERSPECTRUM MODELS WITH APPLICATION TO AIRCRAFT FUSELAGE VIBRATION PREDICTION

Kurzfassung

The wall pressure wavenumber spectra on an aircraft fuselage are calculated analytically and numerically through two-dimensional Fourier transform of the cross-spectral models. The coherence lengths in the streamwise and spanwise directions and the convection velocity required in the cross-spectral models are provided from a flight test with DLR's research aircraft ATRA-A320. A parametric study on the coherence lengths, the convection velocity and the flow angle is performed on the analytical wavenumber-spectrum formulation. The impact of the surface microphone array size and resolution, noise and window function on the derived wavenumber spectra is studied by comparing numerical with analytical results. The fuselage vibration according to different wavenumber-spectrum formulations and the measured spectra as excitation sources is calculated with Statistical Energy Analysis. The obtained vibration spectra in one-third octave bands are compared to the measured vibration spectra. The effect of the parametric changes in the wavenumber-spectral model on the resulting wavenumber spectra is illustrated. Furthermore, the impact of the wavenumber spectra change on the resulting vibration spectra is studied and discussed.