Numerical Simulation of Surface Pressure Fluctuations in Complex Geometries

Surface pressure fluctuations due to turbulent flow over submerged bodies can cause vibration in the surface of the body which, in turn, may radiate noise. In order to predict the structural vibrations responsible for the acoustic radiation, the wavenumber/frequency spectrum of the pressure fluctuations must be known. Experimental data and analytical methods to predict surface pressure spectra currently exist only for simple flows. A computational tool is proposed here to predict surface pressure fluctuations in turbulent flow over practical flow configurations. Large eddy simulation (LES) methodology will be developed and validated for multi-domain body- fitted curvilinear BFC grids in Phase I with particular emphasis given to the issue of filtering on BFC grids. The LES methodology will be extended to hybrid (structured/unstructured) grids in Phase H. The Phase I study will demonstrate the feasibility of LES methodology with a finite volume formulation on BFC grids for predicting surface pressure fluctuations on simple flows. The effect of grid skewness on accuracy of LES predictions will be assessed and recommendations will be made for further development and validation in Phase H. The Phase III study will compare the accuracy and computational requirements to calculate more complex flows with structured, unstructured, and hybrid grids.