A New Algorithm to determine the 3D Location of Particles in a flow using Cylindrical Interferometric Out-Of-Focus Imaging
Résumé
The ability to simultaneously determine the 3D location, velocity, and size of droplets, bubbles or more complex particles remains a challenge for numerous applications. A new interferometric out-of-focus imaging setup has been recently developed to determine the 3D location and velocity of a particle. With this setup, the resulting interferograms are elliptical, and their ellipticity provides the longitudinal location of the particle. The main difficulty lies in accurately determining this ellipticity, especially for interferograms with significant overlapping. Here, we propose a new algorithm based on the gradient pair vectors (GPV) method. After a complete description of the algorithm, examples are given of its application to a large set of experimental and synthetic images, illustrating the effectiveness of the proposed ellipse-fitting approach even for very complex configurations. This new algorithm should have significant applications for the analysis of complex 3D multiphase flows such as encountered, for example, in nuclear engineering, fuel injection systems, or even meteorology.