CAJ | 학술논문

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.
대수력직경위2.5 mm적정방형소통도내적비우돈류체-담기적수직향상량상류동류형진행료가시화실험,공질분별위:농도0.2%적취병희선알(PAM)화0.2%적황원효(XG)수용액,표관기속0.1～100 m/s,표관액속0.01～6 m/s.관찰도적전형류형유:탄상류、교반류、탄배상류화배상류,기중탄배상류미견우수-공기상승류동.재PAM-담기실험중발현료일충신류형-포상-탄상류.통과류형도대비,발현비우돈류체적교반류구역교우돈류체착,탄상-교반류전변선야명현우이,비우돈류체적점성대류형전변적영향교대.
Experiments of visualized nitrogen/non-Newtonian fluid two-phase upward flow are conducted in a square minichannel with a hydraulic diameter of 2.5 mm.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.