Abstract A new method for detecting a gas–water interface in a circular pipe is proposed. In the method, ultrasonic signals are used for non-intrusive measurement and three types of signal analyses are conducted: time-of-flight (TOF), local amplitude, and global amplitude analyses. Horizontal, 45° inclined, and vertical pipe configurations were used to verify the applicability of the proposed detection method. In the case of a horizontal pipe with an acoustic beam directed perpendicular to the water surface, TOF and amplitude analyses detect the water level. In the cases of a horizontal pipe with an acoustic beam directed parallel to the water surface, a 45° inclined pipe, and a vertical pipe, when the pipes were filled with water, TOF analysis was not applicable and amplitude analysis detects the water level. In conclusion, the gas–liquid interface in circular pipes could be analyzed qualitatively and quantitatively through the proposed non-intrusive acoustic method.

中文翻译：

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各种角度倾斜圆管气水界面的非侵入式检测

摘要 提出了一种检测圆管气水界面的新方法。在该方法中，超声波信号用于非侵入式测量，并进行三种类型的信号分析：飞行时间 (TOF)、局部幅度和全局幅度分析。水平、45° 倾斜和垂直管道配置用于验证所提出的检测方法的适用性。对于声束垂直于水面的水平管道，TOF 和振幅分析可检测水位。在声束平行于水面的水平管、45°倾斜管和垂直管的情况下，当管道充满水时，TOF分析不适用，振幅分析检测水位。综上所述，