Computation of Noise Radiated from a Turbulent Flow over a Cavity with Discontinuous Galerkin Method
Noise generated from cavity flows has been the subject of many studies due to its frequent encounters in engineering applications. Cavity noises are affected by various parameters such as boundary layer thickness, length-to-depth ratio, Mach and Reynolds numbers, which can be categorized into two modes, i.e., shear-layer and wake modes [RCB02]. In shear-layer mode, noises are generated from oscillations of mixing layer which are sustained by acoustic feedback. On the other hand, they are generated from vortex shedding in wake mode. For shorter cavities and for low Mach numbers, shear-layer mode is likely to occur. When the Reynolds number increases or boundarylayer thickness is reduced, the chance of occurrence of wake mode increases. While possible frequencies can be predicted analytically, it is difficult to predict the dominant ones and their amplitudes by an analytical method due to various parameters.
KeywordsDiscrete Fourier Transform Boundary Layer Thickness Sound Pressure Level Discontinuous Galerkin Method Wake Mode
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