High Pressure Annular Two-Phase Flow in a Narrow Duct: Part II—Three-Field Modeling

Abstract

This paper outlines the development of a three-field modeling approach in annular flow and the predictive capability of an analysis code. Models have been developed here or adapted from the literature for the thin film near the wall as well as the droplets in the vapor core, and have been locally applied in a fully developed, two-phase adiabatic boiling annular flow in a duct heated at the inlet at high pressure. Numerical results have been obtained using these models that are required for the closure of the continuity and momentum equations. The two-dimensional predictions are compared with local void fraction and droplet velocity (using a hot film anemometer), and average void fraction (using gamma densitometry) for a refrigerant fluid flowing in a narrow vertical duct with a cross-section aspect ratio of 22.5. Predicted results match the experimental data well for high void fraction annular flows, validating the overall modeling approach. [S0098-2202(00)01002-6]