Three-dimensional reconstruction of combustion flames through optical fiber sensing and CCD imaging

This paper presents the design and implementation of an imaging fiber based tomographic system for the three-dimensional (3-D) visualization and characterization of combustion flames. Eight imaging fiber bundles coupled with two RGB CCD cameras are used to acquire flame images simultaneously from eight different directions around the burner. The fiber bundle consists of 30k picture elements and has an objective lens with a 92° angle of view, offering a wide field of view. A series of system calibrations was conducted to ensure system accuracy. Computer simulations were also undertaken to evaluate different tomographic algorithms for 3-D reconstruction of flame cross-sections based on eight image projections obtained from the imaging system. Preliminary experimental results obtained on a gas fired test rig demonstrate that the system is capable of 3-D visualizing and characterizing flames.