Laser imaging of fuel injection systems and combustors

The control of NOx, stability and re-light in combustors is strongly influe nced by the patternation of the fuel and its subsequent mixing with air. Th is paper reviews imaging approaches to two-phase flow and fuel vapour. The two main methods discussed are laser-induced fluorescence (LIF) for the ima ging of volume fraction of fuel vapour or the volume fraction of liquid fue l and laser sheet drop-sizing (LSD) for the imaging of fuel droplet size. A range of practical applications is presented to illustrate the techniques, these include a I atm lean prevaporized premixed (LPP) combustor, a study of the pilot zone of a double annular system and the study of spray pattern ation and droplet size for a variety of fuel injectors.