Finite element modeling of brass musical instruments

This paper studies the contributions of mouthpiece and tubing to the acoustical properties of three nominally similar musical instruments from the brass family: trumpet, cornet and flugelhorn. Geometries of these instruments were used for an axisymmetric FEA simulations of the harmonic response to sinusoidal pressure at the mouthpiece. ANSYS software was used, with elements modelling the Helmholz equation. Frequency spectra for these instruments were obtained by FFT from sustained tones produced by advanced players under controlled studio conditions and significant differences were noted. While the FEA did not model the players’ lips the sound transmission functions produced by these analyses again showed significant differences between instruments and generally favourable agreement with the measured spectra, in particular a strong 3rd harmonic for the cornet and a strong fundamental for the flugelhorn. Actual mouthpieces were not interchangeable but the FEA model was able to show that the mouthpiece and tubing each make a substantial contribution to the spectral differences. As expected the tubing had greater effect on the lower harmonics while the mouthpiece affected predominantly the mid range (around 700 Hz for the trumpet and cornet, and 1100 Hz for the flugelhorn).