STUDY OF A DIFFUSION PUMP EJECTOR

Numerical and experimental investigations of a low gas density ejector in the operation regime of a diffusion vacuum pump are presented. The calculations of a real ejector were performed on the basis of Navier- Stokes equations. The analysis of the detailed flow structures is base d on the comparison with the experimental values for the compression r atio. A previously unknown effect of the appearance of a steady annula r vortex close to the diffusor wall was found. The operation regimes, in which a return flow is formed, were determined.