The article is devoted to the development of a gas-dynamic model of the motion of polydisperse media in areas of arbitrary shape, simulating the configuration of high-speed separators for dry cleaning, in particular, nozzle separators. A mathematical model and a calculation scheme have been created that allow taking into account the influence of solids polydispersion on the structure of the gas and dust flow in the flow path of the separator in a wide range of changes in the determining parameters. Particular attention is paid to the modes of motion of gaseous dispersed flows in curved channels (nozzles) with a large mass content of the dispersed phase in the inlet section of the channel (nozzle). On the basis of the developed mathematical model, it was possible to take into account the influence of particles bouncing off the nozzle walls on the distribution of characteristics of the multiphase continuum in the entire area under consideration. It is shown that taking into account the rebounded particles in a wide range of changes in the size of dispersed inclusions leads in a model to a significant deceleration of the flow in the separator
