竖直圆管内泡状流界面参数分布特性

采用双头光纤探针对内径为50 mm竖直圆管内空气-水两相泡状流界面参数径向分布特性进行了实验研究。气液两相表观速度变化范围分别为0.004～0.05 m/s和0.071～0.283 m/s。结果表明，竖直管内向上泡状流局部界面面积浓度（IAC）、空泡份额及气泡频率径向分布相类似，即气相流速较低时管道中间很大范围内以上3个局部界面参数几乎恒定，近壁区迅速下降到较低值；随气相流速的增加，局部界面参数在管道中心出现峰值。本实验中气泡聚合与破碎现象较少发生，索特平均直径沿径向近似均匀分布，且随气液两相流速变化很小。通过气泡横向受力解释了局部界面参数分布的影响机理。

Interfacial Parameter Distribution of Bubbly Flow in Vertical Circular Tube

The experimental study was performed on characteristics of interfacial parameters radial distribution of air-water bubbly flow by using a two-head optical fiber probe in a vertical circular tube with the inner diameter of 50 mm. The gas and liquid superficial velocities cover the ranges of 0.004-0.05 m/s and 0.071-0.283 m/s, respectively. The results show that the local interfacial area concentration (IAC), bubble frequency and void fraction nearly have the same distribution, that is, the three interfacial parameters almost keep constant along radius except in the near wall region where it falls to a low value with a low gas velocity; as the gas velocity increasing, the interfacial parameter has a peak value in the core region of circular tube. In the experiment, few bubble coalescence and breaking up occur, and the bubble Sauter mean diameter distribution in the radial direction is approximately uniform and changes little with gas and liquid velocities. The lateral bubble force in cross section is considered to explain the local parameters distribution pattern.