基于WMS的无旋和螺旋气液两相流流型及空泡份额实验研究

为探究气液两相流流型从无旋状态转变为螺旋状态前后的流型特征及空泡份额时空分布特性，基于高速摄影仪和自主开发的丝网传感器（WMS）测量技术，对内径为30 mm的水平管内起旋装置作用下空气-水两相流的相态时空演变特性进行了可视化实验研究。结果表明，在起旋器诱导的离心力作用下，流场内存在明显的气泡聚并行为和液滴沉积现象，其中，泡状流将转变为螺旋气柱流，塞状流转变为螺旋间歇流，弹状流转变为螺旋环状流，环状流转变为螺旋丝带流；相比于弹状流和环状流，泡状流和塞状流的截面平均空泡份额在起旋器出口波动幅值明显减弱，但离心力场并未明显改变各流型从无旋状态转变为螺旋状态前后的截面平均空泡份额。 

Experimental Study on Flow Patterns and Void Fraction of Non-swirling and Swirling Gas-liquid Two-phase Flow Based on WMS

In order to explore the flow pattern characteristics and the spatial-temporal distribution characteristics of void fraction before and after the gas-liquid two-phase flow pattern changes from non-swirling state to swirling state, based on the high-speed camera and the self-developed wire mesh sensor (WMS) measurement technology, the spatial-temporal evolution characteristics of the phase state of the air-water two-phase flow under the action of a swirling device in a horizontal tube with an inner diameter of 30 mm are studied visually. Under the centrifugal force induced by the swirler, there are obvious bubble coalescence behavior and droplet deposition phenomena in the flow field. Among them, the bubble flow will be transformed into swirling gas column flow, the plug flow into swirling intermittent flow, the slug flow into swirling annular flow, and the annular flow into swirling ribbon flow; compared with slug flow and annular flow, the fluctuation amplitude of the section average void fraction of bubbly flow and plug flow at the swirler outlet is significantly weakened, but the centrifugal force field does not significantly change the section average void fraction of each flow pattern before and after the transition from non-swirling state to swirling state.