竖直窄矩形通道内弹状流液弹中分区特性研究

弹状流的液弹部分受气弹尾部影响，其水力特性参数沿流动方向存在分区的不一致性。本文对竖直窄矩形通道中弹状流液弹内参数的分布特性进行了研究。结果表明：液弹内气泡在近壁面附近所受径向力较为平衡，气泡频率较大；随着远离气弹尾部，管道中间气泡频率逐渐增大。根据气泡频率波动变化将液弹分为3个区域，尾流区占液弹长度的40%～45%，过渡区占10%～15%，主流区占40%～50%。尾流区和主流区内，空泡份额呈“三峰型”分布；随着气相流速的增加，尾流区内近壁面处峰值逐渐增大，管道中间峰值逐渐下降，但主流区内情况相反。气泡直径随气相流速的增大而变大，且液弹内气泡聚合和破碎现象较少。

Flow Characteristics of Different Regions of Liquid Slug Region in Vertical Narrow Rectangular Channel

The liquid slug region of slug flow affected by the wake of Taylor bubble, the hydraulic characteristic parameters of slug flow have different characteristics in different regions alone the flow direction. In this paper, the distribution characteristics of local parameters in slug flow in a vertical narrow rectangular channel were studied. The results show that the radial force of the bubble near the wall is relatively balanced and the frequency of bubbles near the wall is larger. The frequency of bubble in the middle of pipe increases gradually as it moves away from the Taylor bubble wake. According to the fluctuation of bubble frequency, the liquid slug region can be divided into three regions: The wake region accounts for 40% to 45% of the length of the liquid slug region, the transition region accounts for 10% to 15%, and main liquid region accounts for 40% to 50%. Since the wake region accounts for large, its influence cannot be neglected. The void fraction presents a “three-peak” distribution in the wake region and the main liquid region. With the increase of gas velocity, the peak value near the wall in the wake region gradually increases, and the peak value in the middle of the pipeline gradually decreases, but the situation is opposite in the main liquid region. The bubble diameter increases with the gas velocity, and the phenomenon of bubble coalescence and breakup in liquid slug region is less.