Flow of two‐phase carbon dioxide through orifices

Abstract

AbstractExperimental flow rate data are presented for saturated liquid, saturated vapor, and two‐phase liquid‐vapor carbon dioxide through a convergent nozzle and a square‐edged orifice. The data cover the range from the triple‐point pressure to the critical pressure. Charts have been prepared for this complete range at critical flow. Results are also presented for subcritical flow.The tests at various back pressures indicate that the saturated liquid behaved as a cold liquid without evaporation ahead of the throat.Saturated vapor became supersaturated in the nozzle, and the vapor behaved as if no condensation occurred.Equations are presented for the flow rates of saturated vapor, and two‐phase mixtures in the critical flow region.A Mollier (pressure‐enthalpy) diagram is used to determine the flow rates of saturated vapor and two‐phase mixtures where supersaturtation takes place. In these cases, the lines of constant specific volume or density are extrapolated from the superheated region into the normal two‐phase region to obtain values corrected for supersaturation.