A Novel 3-D Reconstruction Method of Liquid Film Based on Scanning Laser-Induced Fluorescence

The accurate measurement of liquid film in the pipe is essential for process monitoring and industrial safety. Three-dimensional measurement can effectively improve the measuring accuracy. However, there are few measurement methods and limited spatial resolution. In this article, a new scanning laser-induced fluorescence (SLIF) method is proposed to perform the 3-D reconstruction of liquid film in the pipe with high precision. Combined with Zhang’s calibration method, the imaging magnifications of slice images are evaluated and corrected. In order to eliminate the motion smear in fluorescence imaging, a prediction model is established. In addition, an innovative spatial distortion correction method has been developed to reconstruct circumferential liquid film, and the mean absolute percentage error is less than 1.56%. Furthermore, an advanced contour interpolation method based on inverse distance transformation and volume rendering method is performed sequentially to achieve 3-D reconstruction. Moreover, the volume measurement is carried out and concludes that the relative error of reconstruction results is 2.38%, which verifies the reliability of the 3-D reconstruction method based on SLIF. Finally, the 3-D reconstruction of the falling liquid film is conducted, which characterizes the detailed structure of the liquid film. These results supply key solutions for 3-D reconstruction and can be accomplished successfully in experimental research.