螺旋直径对螺旋管泡状流截面分布特性的影响

研究了不同螺旋直径螺旋管中泡状流的相界面参数（空泡份额、相界面浓度、气泡尺寸等）的截面分布特性。通过图像法标定了电导探针的测试精度，并通过合理地处理双头电导探针，得到了螺旋管中泡状流的空泡份额、相界面浓度和气泡数量频率的定量分布云图。为进一步量化地描述相界面参数的分布特征，采用统计方法定义了截面平均参数、相界面离散系数和气泡平均聚集坐标来表征其特性。实验结果表明，随着管道旋转直径的增大，气泡截面平均空泡份额有所下降，分布范围缩小，平均聚集坐标向上方和外侧移动，气泡尺寸整体上有所下降。

Effect of Helical Diameter on Cross-sectional Distribution Characteristic of Bubbly Flow in Helical Tube

The cross-sectional distribution characteristics of the phase interface parameters (void fraction, phase interface concentration, bubble size, etc.) of bubbly flow in helical tubes with different helical diameters were studied. The measurement accuracy of double-sensor conductivity probe was calibrated by imaging method, and then the quantitative distribution profiles of void fraction, phase interface concentration and number frequency of bubbles in helical tubes were obtained. In order to describe quantitatively the distribution characteristics of phase interface parameters, the cross-sectional average parameters, phase interface dispersion coefficient and bubble average aggregation coordinates were defined by statistical methods to characterize the distribution characteristics. The experimental results show that, with the increase of the rotating diameter of the pipe, the average void fraction of the bubble section decreases, the distribution range decreases, the average locations of aggregation move to the topside and the outside, and the overall bubble size decreases.