Volume Measurement of Taylor Bubble Based on Laser-Induced Fluorescence

Gas–liquid intermittent flow commonly occurs in industrial processes such as oil well production, pipeline transportation, and nuclear reactor cooling. Investigation of Taylor bubble behavior in the intermittent flow is essential for safe operation and heat and mass transfer efficiency enhancement. Since the gas–liquid interface contains fluctuations, it is difficult to obtain high-resolution bubble surface with traditional measurement methods. In this article, a novel laser-induced fluorescence (LIF) based 3-D reconstruction and volume measurement method for Taylor bubble is developed. First, LIF technique is improved to not only detect the bubble section contour, but also measure the bubble velocity. In addition, to increase the axial spatial resolution of bubble section contour sequence, a volumetric image interpolation algorithm suitable for bubble morphology is developed. And the marching cubes algorithm is further introduced to reconstruct the Taylor bubble surface to achieve fine 3-D visualization. More importantly, the Monte Carlo method is combined with the reconstruction results to realize the volume measurement of irregularly shaped Taylor bubbles. Finally, the relationship between length and volume is established based on the measurement results, through which the volume of Taylor bubbles can be predicted by the easy-to-measure bubble length. The experimental results conclude that the reported volume measurement method for Taylor bubble is valid with high precision, and the numerical simulation data are also used to verify the effectiveness of the bubble volume prediction model.