The sound generation of labial organ pipes is a complex physical process, since it involves fluid flow and acoustical phenomena inherently coupled. When a pipe is played air flows through the pipe foot and a thin jet of air emerges in the windway. As this jet hits the upper lip an edge tone is produced, which provides the excitation for the acoustic resonator. The edge tone and its interaction with the resonator is of key importance to the sound quality of the pipe. We report and evaluate CFD simulations of the aforementioned air jet using 2D and 3D geometries with a laminar and a Large Eddy Simulation (LES) model. In the first configuration no upper lip is present and the jet can be considered free. The quality of simulation results is assessed by means of comparison to reproducible hot wire anemometer measurements carried out on a high precision pipe foot model. With the upper lip being part of the model, the jet shows oscillating behavior around the edge. We also present flow simulation of this setup and evaluate the mode frequencies of the resulting edge tone. It is found that by extending the flow model into three dimensions the quality of CFD simulations is improved remarkably, achieving better fit to measurement results both in the free jet and edge tone configurations.
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