Numerical Approach for Aerodynamics around a tone hole with a moving pad: an example solving moving boundary problems with topological change
* Presenting author
In this paper, we discuss the numerical reproducibility of the compressible fluid behavior around a tone hole of woodwind instruments by using compressible Large Eddy Simulation (LES). In particular, we focus on the situation that the tone hole is opened and closed with moving a pad above the tone hole and the change of the pitch occurs. From the numerical point of view, this is a moving boundary problem with topological change. Our numerical models are of 2D and 3D analogs of Keefe's experimental model, for which a tone hole is placed at the center of the resonance tube. To reproduce the opening and closing the tone hole, the pad should be moved continuously and we developed a method solving this problem. As a result, the process of "open - close - open” in order is completely reproduced. Namely, the change of the pitch with opening and closing the tone hole is well reproduced, and the details of complex vortices near the tone holes can be clarified by these numerical calculations. Our numerical results are in agreement with Keefe's experiment results. Therefore, we solved the moving boundary problem with topology change under the situation of acoustics of fluid-structure interactions.