Analysis of radiated power from a plate in a turbolent boundary layer

The paper presents an innovative solution for the analysis of the structural and acoustic response of a plate wetted by a turbulent boundary layer. A reference solution is assembled by using a standard modal expansion based on the "in vacuum" structural mode shapes. This modal solution requires a computational effort that could be easily become unacceptable at increasing excitation frequency, since the number of required operation for each excitation frequency (evaluation of the joint and cross acceptances integrals) are proportional to N2: N denotes the number of involved modes. The innovative solution is based upon a reduction of the dimensions of the plate, and accordingly an increase of the original damping values. Both the steps allow representing the energy of the original system by using the same modal expansion at decreasing computational costs. The criterion and the limits of the scaling procedure are also discussed. The depicted procedure is completely general: it can be applied to any computational scheme working with the modal approach, such as the finite element method. Results belonging to this latter method will also be shown.