aInria
bAix Marseille Univ, CNRS, Centrale Marseille, LMA, UMR 7031, Marseille
Abstract :
Our project develops an optimisation software (OpenWind)
for wind instrument making. The approach is based on a
strong interaction with makers and musicians, aiming at
defining interesting criteria that should be optimized, from
their point of view. After a quantitative transcription of
these
criteria, under the form of a cost function and a design
parameter space, we implement state-of-the-art
numerical techniques (finite elements method (FEM), full
waveform inversion (FWI), various
optimisation techniques) with a flexible framework (in
terms
of models, formulations, coupling terms…) in order to solve
the optimisation problem. More precisely, we exploit
the fact that the sound waves inside the instruments are
solution to acoustic equations in pipes, which gives us
access to the full
waveform inversion technique, that can be used in both
time and
frequency domains. The chosen methodologies weekly
depend on the criterion and can be adapted to
multiple physical situations (non constant temperature,
multimodal decomposition in the pipe, coupling with an
embouchure, …), which can therefore be modified a
posteriori. The goal is to proceed iteratively between the
instrument makers and the numerical optimisation tool
(openwind) in order to achieve, finally, criteria that
are representative in terms of instrument tone and ease of
playing.