Prediction of Rotorcraft Noise with a Low-Dispersion Finite Volume Scheme

A low-dispersion finite volume (LDFV) scheme on curvilinear meshes is developed and applied to rotorcraft noise prediction. This scheme minimizes the numerical dispersion errors that arise in modeling convection phenomena, while keeping dissipation errors small. It is accomplished by special high-order polynomials that interpolate the properties at the cell centers to the left and right sides of cell faces. A low-pass filter has also been implemented that removes high-frequency oscillations near shock waves. This scheme has been retrofitted into a version of the finite volume code TURNS. The modified solver, referred to as TURNS-LDFV, is shown to yield good results for high-speed impulsive noise applications. The LDFV scheme is also shown to be useful for capturing the blade-tip vortex core structure and its evolution.

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