High-speed Planar Laser-induced Fluorescence Imaging Research Articles

Investigation of Flame Evolution in Heavy Oil Boiler Bench Using High-Speed Planar Laser-Induced Fluorescence Imaging

Over recent years, much attention has been paid to the performance evaluation of industrial-type burners. The ignition and stable combustion process are of great significance in assessing the quality of burner. The planar laser-induced fluorescence (PLIF) technique can be applied to heavy oil boilers, extending this technique to engineering applications. Considering the complex environment of the bench test, measures such as temperature control and moisture proofing are made to improve the possibility of detection using PLIF. In this paper, an experimental investigation of flame growth following ignition is reported. A wrinkled structure could be observed from the configuration of the ignition flame; its trajectory will be depicted. The results showed that the wrinkled structure developed downward, i.e., by deviation from the direction of the airflow. The displacement velocity of the flame was used to describe the combustion rate. Good agreement was obtained for the flame shapes of both forced ignition and autoignition. In addition, the center of combustion deviated from the center of boiler, possibly due to some irregularity in the burner’s assembly which was critical to the design of the combustion chamber.

Development and application of a high-speed planar laser-induced fluorescence imaging system to evaluate liquid and vapor phases of sprays from a multi-hole diesel fuel injector

A high-speed imaging system capable of acquiring elastic scattering images and planar laser-induced fluorescence (PLIF) images in a near-simultaneous fashion has been developed. Acquiring both elastic scattering and PLIF images enables the liquid phase to be discriminated from the vapor phase. High-speed imaging allows the temporal evolution of flow structures to be evaluated. Images of sprays from a multi-hole diesel fuel injector operating under engine-like conditions were acquired. The vapor phase images reveal intricate fluid dynamic structures that exhibit a high degree of variability, indicative of a turbulent gas jet.