AbstractAs a part of the development of a numerical method of close capture exhaust systems for machining devices, a test rig recreating a situation similar to a grinding operation, but in a perfectly controlled environment, was produced. The properties of the obtained spray of solid particles were initially characterized using particle tracking velocimetry (PTV), in order to obtain input and validation parameters for numerical simulations. The dispersion of a tracer gas (SF6), emitted simultaneously with the particle jet, was then studied experimentally. This approach assumed that the dispersion of such a gas was representative of that of finer particles, whose aerodynamic response time is negligible. Finally, complete modelling of the test rig was achieved to allow comparison with experimental results and thus to progress towards validation of the models used to describe a dispersion of a tracer gas representative of finer particles. The commercial software Fluent was used for the numerical simulations.