An effective approach of simulating subsonic fluid dynamics on a cluster of non-dedicated workstations is presented. The approach is applied to simulate the flow of air in wind instruments. The use of local-interaction methods and coarse-grain decompositions lead to small communication requirements. The automatic migration of processes from busy hosts to free hosts enables the use of non-dedicated workstations. Simulations of 2D flow achieve 80% parallel efficiency (speedup/processors) using 20 HP-Apollo workstations. Detailed measurements of the parallel efficiency of 2D and 3D simulations are presented, and a theoretical model of efficiency is developed and compared against the measurements. Two numerical methods of fluid dynamics are tested: explicit finite differences and the lattice Boltzmann method.