摘要
对水力直径为2.5 mm的正方形小通道内的非牛顿流体氮气的垂直向上两相流动流型进行了可视化实验,工质分别为:浓度0.2%的聚丙烯酰胺(PAM)和0.2%的黄原胶(XG)水溶液,表观气速0.1～100 m/s,表观液速0.01～6 m/s。观察到的典型流型有:弹状流、搅拌流、弹环状流和环状流,其中弹环状流未见于水-空气上升流动。在PAM-氮气实验中发现了一种新流型-泡状-弹状流。通过流型图对比,发现非牛顿流体的搅拌流区域较牛顿流体窄,弹状-搅拌流转变线也明显右移,非牛顿流体的黏性对流型转变的影响较大。
Experiments of visualized nitrogen/non-Newtonian fluid two-phase upward flow are conducted in a square minichannel with a hydraulic diameter of 2.5 ram. Two non-Newtonian aqueous solutions are used as the working fluids, namely, 0.2% polyacrylamide （PAM） solution, and 0.2% xanthan gum （XG） solution. The gas superficial velocity ranges from 0.1 to 100 m/s and liquid superficial velocity from 0.01 to 6 m/s. Some representative flow patterns are observed as slug flow, churn flow, slug-annular flow, and annular flow, while the slug-annular flow is not found in nitrogen-water two-phase flow. A new flow pattern, named bubbly-slug flow, is found in nitrogen-PAM two-phase flow. The comparisons of flow regime maps show that the churn flow region of gas/non-Newtonian two-phase flow is narrower than that of gas/water flow; and the slug-churn transition limit of gas/non-Newtonian flow moves rightward apparently. It indicates that viscosity of the non-Newtonian solution influences the flow pattern and its transition remarkably.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2009年第11期1870-1874,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.50576076)
关键词
非牛顿流体
小通道
两相流
流型
non-Newtonian fluid
minichannel
two-phase flow
flow pattern
