Modeling of powder-gas flows near a suction port in a multiply-connected domain with a rotating cylinder

A mathematical model for the dynamics of powder-gas flows near suction ports is discussed. An impermeable rotating cylinder is placed in the operating zone of these ports. The local ventilation exhausts from a roll-turning machine are numerically studied. It is shown that the neglect of the air flow induced by the rotating cylinder causes considerable computational errors. In order to determine the necessary amount of aspiration, the ratio of the suction velocity to the rotational velocity of the cylinder is used as a one of the basic characteristics of the process.