Interactive demo of Openwind, an online tool for simulating the acoustic response of wind instruments

Openwind is a Python library (free and open source) dedicated to the simulation of wind instruments. It allows the calculation of the acoustic response in the frequency domain (impedance or admittance) or in the time domain (impulse response), from the geometry of the instrument (main bore, side holes, and valves). The wave propagation model can take into account thermo-viscous effects, non-uniform temperature, multiple radiation conditions through boundary conditions, etc. It is also possible to simulate the sound of brass, reed, and flute instruments. Discretization is done in space with 1D spectral finite elements and in time with energy consistent finite differences. The sensitivity of the instrument to design parameters can be calculated and visualized. A graphical interface, freely available online (https://demo-openwind.inria.fr), gives the possibility to perform frequency domain simulations without coding. It is mainly used by students (in science or musicology) and instrument makers (hobby, student, or professional). With this interface, it is easy to observe the effect of a geometric modification on the acoustic response (resonance frequency, mode shape, etc.) or a change in temperature or radiation conditions. The numerical aspects (mesh, order, etc.) are set automatically and can be further refined using the Python library.