Transduction of Boundary‐Layer Noise by a Rectangular Panel

The response and consequent sound radiation of a thin rectangular panel excited by convected boundary‐layer turbulence has been examined. By taking averages over a frequency band, and including many modes in this average, the detailed characteristics of the system are bypassed and only gross features such as panel modal density, ratio of radiation to total resistance, and the boundary‐layer characteriqtics are of interest. A large proportion of the sound power is transmitted in the region of the hydrodynamic coincidence conditions. The hydrodynamic coincidence frequency is the most important feature in determining the shape of the transmitted acoustic‐power spectrum and the power laws for the total radiated power. The change in power‐law dependence with the flow velocity and the panel thickness is satisfactorily explained. Excellent agreement between theory and experiment serves to verify the basic assumptions of the theory.