  Since its origins, lattice-Boltzmann methods have been restricted to
rectangular coordinates, a fact which jeopardises the applications to problems
with cylindrical or spherical symmetries and complicates the implementations
with complex geometries. However, M. Mendoza recently proposed in his doctoral
thesis a general procedure (based on Christoffel symbols) to construct
lattice-Boltzmann models on curvilinear coordinates, which has shown very good
results for hydrodynamics on cylindrical and spherical coordinates. In this
work, we construct a lattice-Boltzmann model for the propagation of scalar
waves in curvilinear coordinates, and we use it to determine the vibrational
modes inside cylinders, trumpets and tori. The model correctly reproduces the
theoretical expectations for the vibrational modes, and exemplifies the wide
range of future applications of lattice-Boltzmann models on general curvilinear
coordinates.
