A wavenumber domain analysis of the coupling of a structural mode and flow turbulence

Previous studies on the coupling of a structural mode and the pressure field induced by a turbulent boundary layer have concentrated on the determination of the relative contributions of two regions of the wavenumber domain; the high-wavenumber region at and near hydrodynamic coincidence and the low-wavenumber region at and near the structural free wavenumber. The corresponding contribution to the coupling by the intermediate-wavenumber region that lies between the high- and low-wavenumber regions has not received proper attention. In this paper, formulas to estimate the contributions to the coupling by the three wavenumber regions are derived, and numerical results are evaluated and compared. It is found that situations exist in which the contribution by the intermediate-wavenumber region may be significant. [Work supported by ONR.]