Turbulent boundary layer induced vibration up to high frequencies by means of local energy methods

Abstract

The local energy method developed in the last years revealed appropriate in medium and high frequencies and supplies an accurate description of the spread of vibration and acoustic fields up to high frequencies. Our aim in the paper is to provide a complete description of the turbulent boundary layer (TBL) induced vibration by means of this method, for a simply supported thin plate. The first step in the energy method proof is the characterization of energy input from a given model of the TBL pressure interspectrum. Then, is deduced the uncoherent structural response of the panel, and the uncoherent normal mean square velocity. The latter provides, using the acoustic radiation resistance, a prediction of noise radiating by the panel up to high frequencies. Accuracy of the local energy analysis versus the usual random normal modes decomposition is demonstrated. Ultimately, a numerical parametric survey is given for various internal loss level. Precisely, the link between results provided here and SEA predictions of TBL structural induced vibration is discussed.