Abstract The experiments of co-current vertical upstream air-water two-phase flow in a 66 mm × 66 mm square channel were carried out. The superficial liquid velocity ranges from 0.765 m/s to 1.53 m/s and the superficial gas velocity ranges from 0.0215 m/s to 0.313 m/s, including bubbly flow and cap-bubbly flow. A dual wire-mesh sensors (WMSs) was used to measure the bubbles in the two-phase flow. The local superficial gas velocity from the dual WMSs was compared with the rotameters and most results were within the deviation of 5%. It can ensure the measurement accuracy of the WMSs. The experimental results include the void fraction projection, sectional averaged void fraction variation, time-averaged void fraction profile, gas velocity profile, and the bubble size distribution. Within the range of flow conditions of this paper, the void fraction was relatively uniformly distributed among the cross-section in the bubbly flow and core peak in the cap-bubbly. Both cross-correlation velocity and bubble velocity were used to calculate the gas velocity profiles. Since the bubble lateral displacement, the cross-correlation method trend to miss the correlation caused by small bubbles and get a higher velocity. Bubble velocity was recommended to be used for determining gas velocity profiles. The results of void fraction profiles, gas velocity profiles, and bubble size distributions can be used for the validation of two-phase models of CFD codes. The void fraction predictions of two drift-flux correlations were compared against the experimental data and both models provided reasonable prediction accuracy.

中文翻译：

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基于双丝网传感器的方通道气泡和帽气泡流研究

摘要 在66 mm × 66 mm方形通道内进行并流垂直上游气水两相流实验。表观液体流速范围为 0.765 m/s 至 1.53 m/s，表观气体流速范围为 0.0215 m/s 至 0.313 m/s，包括气泡流和帽气泡流。双丝网传感器 (WMS) 用于测量两相流中的气泡。将双 WMS 的局部表观气速与转子流量计进行比较，大多数结果的偏差在 5% 以内。可以保证WMS的测量精度。实验结果包括空隙率投影、截面平均空隙率变化、时间平均空隙率分布、气体速度分布和气泡尺寸分布。在本文的流动条件范围内，空隙率在气泡流的横截面和帽状气泡的核心峰之间分布相对均匀。互相关速度和气泡速度都用于计算气体速度分布。由于气泡横向位移，互相关方法倾向于忽略小气泡引起的相关性而获得更高的速度。建议使用气泡速度来确定气体速度分布。空隙率分布、气体速度分布和气泡尺寸分布的结果可用于验证 CFD 代码的两相模型。将两种漂移-通量相关性的空隙率预测与实验数据进行了比较，两种模型都提供了合理的预测精度。