Measurements and modelling of turbulent boundary layer excitation and induced structural response on a ship: PART I full scale wall pressure fluctuations

摘要

To comply with the more and more restrictive international standards and regulations forrnnoise and vibration levels on board passenger ships, a renewed interest on secondary N&Vrnsources, with respect to propeller and machinery sources, has been observed. In particular,rnthe increase of ship performances in terms of velocity has been directed on study thernhydrodynamic noise sources and among the others turbulent boundary layer (TBL).rnThe great difficulties encountered in simulating the wall pressure fluctuations (WPF) duernto TBL at high Reynolds numbers and for complex configurations typical of a real shiprnhave pushed the research community to develop models for WPF based on theoreticalrnconsiderations and model scale tests. In particular, scaling laws for pressure spectra havernbeen established at least for simple geometries and flow conditions and models of crossrnspectral density for their spatial characterization have been obtained.rnUnfortunately, model scale tests do not allow reaching Reynolds number valuesrncomparable with full scale conditions. Therefore, to validate current models anrnexperimental campaign devoted to WPF measurements have been performed on the hull ofrna Ro-Ro Pax vessel. Numerical simulations of the flow around the ship hull were performedrnto evaluate mean flow parameters.