This paper presents a theoretical model for the high speed flow of homogeneous air-oil mixtures through converging - diverging ducts. This model is used to investigate the effects of friction, oil density, oil mass fraction in the mixture, duct throat clearance, and duct geometry, on the flowrate through the duct. The results indicate that for homogeneous mixtures the effect of the density is marginal. On the other hand, it was found that the surface friction, the size of throat clearance, and the duct geometry affected significantly the mass flowrate. Increasing the gas to liquid mass ratio increases the leakage. This effect diminishes at large values of the mass ratio.
