Three-dimensional numerical simulation and experimental validation of flows in working chambers of roots blowers with backflow design

Abstract

The backflow design is one way to reduce the noise in the Roots blower. In this paper, the three-dimensional computational fluid dynamics (CFD) models were established to simulate the flows in the working chambers of the Roots blower with and without backflow design, using the dynamic mesh method. And then, the variations of pressure in the cylinder of the Roots blower with backflow design were tested in experiment to validate these CFD models. The result shows the CFD models were appropriate. The backflow could reduce the amplitude of the pressure pulsation in the outlet of the Roots blower more than 50%, but the volume efficiency also be reduced by 3.5%.