Physical modeling of a trombone player’s lips

The creation of a physical model is discussed in the context of the lips of a player/trombone system. The lip model is designed to incorporate the salient features of the physical structure of the lips, especially the geometry and material properties. A finite-element model is developed to approximate this structure, while the aerodynamic system is represented by flow equations solved with a finite difference scheme. To drive this model three pressures are applied. The mouth pressure is generated as a constant lung pressure delivered across an airway resistance; the pressure between the lips is dependent on the stream velocity, and the pressure in the mouthpiece is given by the convolution of the volume velocity with the impulse response of the trombone. Together these drive the oscillation of the finite element lip structure, which may be compared with that of previous models and experimental studies.