Two-Phase, Gas-Liquid Nozzle Flow

摘要

The report describes an experimental investigation of two-phase, two-component, air-water critical and subcritical nozzle flows with an annular/stratified flow pattern. The nozzle exhausted to atmospheric pressure from stagnation pressures of 16 to 55 psia. The quality range was from 2% to 35% with a theoretical gas void fraction range of .4 to 1. A feature of the study was the air-water injection system which was designed to minimize the entrainment of liquid into the gas phase and to minimize interfacial disturbances (waves). A theoretical two-phase, two-component, separated flow model is developed which characterizes annular and stratified flows. An extension of the separated model (the hybrid model) incorporates homogeneous flow theory to describe the thick liquid film flows along with a gas phase 'core' flow with entrainment (annular-mist). The hybrid model reduces to the separated flow model for the case of no entrainment and to the homogeneous flow model for total entrainment. The effects of entrainment and interfacial waves are discussed. The theoretical model is designed to describe the physical flow situation. In this way the potential for further sophistication by incorporating additional features of the real flow situation is enhanced. A simple empirical 'blockage factor' correlation is derived which predicts most of the data within 10%. (Author)