Losses in the suction process of a two-rotor machine with external compression

The mechanisms of occurrence of performance losses during gas suction in an oil-free two-rotor vacuum pump are considered. CFD modeling of the pump operating process is carried out both in the absence of pressure drop and in operating mode. The influence of heating and throttling of gas as it passes through the inlet pipe and fills the cut-off cavity is considered. The reliability of the results of modeling is confirmed by good agreement with experiment. Gas heating during suction has the greatest impact on performance. A formula is obtained for determining losses with an error not exceeding than 6 %. Keywords:two-rotor vacuum pump, suction, losses, performance, CFD modeling alraykov@kstu.ru