Interface measurement technique for liquid film flowing inside small grooves by laser induced fluorescence

During the recent past, an optical investigation method of liquid films flowing within grooves of small dimensions, was developed by our research team. This non-intrusive method, based on the visualization of a transverse flow section, uses the laser induced fluorescence and image processing techniques in order to characterize the geometry of the liquid–gas interface. This article proposes to describe the principle and the practical application of this method and to present its possibilities through a certain number of applications carried out within our laboratory on isothermal flows and two-phase flows running in small grooves.