Abstract We propose a non-intrusive optical method to reconstruct the boundary between the two immiscible liquids under the well separated interfacial configurations. Silicon based PIN (a diode with p-type semiconductor, a lightly doped intrinsic region and an n-type region) photodiodes are used in reverse biased photovoltaic mode and extent of attenuation in the intensity of light is employed to relate the phase fraction (h/b) with obtained current signals. Phase fraction is found to have exponential relationship with the non-dimensional optical signals and is used to reconstruct the interface profile for different phase associations. The optically acquired interface profiles are in close agreement with the visual inspections for both the inclined and curved phase boundaries. Moreover, the present system is found to capable of characterizing the transient variations of the interface. This has been examined by successful prediction of interface oscillations and transient, random wavy profiles. It has also been established that preset photodiode array could be employed for measurement of flow rates and local phase fractions under the stratified regime.

中文翻译：

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分层液体间界面重建的光学装置的提议

摘要 我们提出了一种非侵入式光学方法来重建分离良好的界面构型下两种不混溶液体之间的边界。硅基 PIN（具有 p 型半导体、轻掺杂本征区和 n 型区的二极管）光电二极管用于反向偏置光伏模式，并采用光强度衰减程度来关联相位分数 (h /b) 获得的电流信号。发现相位分数与无量纲光信号具有指数关系，并用于重建不同相位关联的界面轮廓。光学获取的界面轮廓与倾斜和弯曲相边界的目视检查非常一致。而且，发现本系统能够表征界面的瞬态变化。这已经通过成功预测界面振荡和瞬态随机波浪轮廓进行了检验。还已经确定，预设光电二极管阵列可用于测量分层制度下的流速和局部相位分数。