An Equation for the Critical Mass Velocity of Homogeneous Vapor-Liquid Mixtures at Low Pressures

Abstract

Equations have been developed expressing the critical mass velocity, (Gc)s, and the isentropic expansion coefficient, k, of a single-component, homogeneous vapor-liquid mixture at low pressures in terms of tabulated thermodynamic properties. With these parameters, two-phase flow relations can be developed which are analogous to the relations governing the flow of single-phase compressible fluids, most readily formulated in terms of Mach numbers. The computed values of k for saturated steam agree favorably with those reported in the literature of steam-turbine design.