Abstract
Lift-off heights of three well-studied reference jet fuels and three surrogate jet fuels with similar pre-vaporized combustion behavior are measured in a piloted spray burner using chemiluminescence imaging. The spray burner consists of a central tube of two-phase flow, resembling an open-pipe atomizer, and a surrounding hydrogen/air pilot flame to assist ignition of the liquid fuel. It is found that the lift-off behaviors of the reference jet fuels are generally comparable, with the main differences occurring for the most transient condition. However, the surrogate fuels do not reproduce the lift-off heights of the reference fuels due to discrepancies in the spray behaviors between the two. In particular, the differences in viscosity are inferred to be the primary reason for the variations in the flame heights. This investigation confirms that the physical properties of …