Spatial Heat Release and Equivalence Ratio Measurements in Liquid-fuelled Bluff Body-stabilized Flames using Chemiluminescence Imaging

摘要

A method for determining time-averaged, spatial distributions of combustion process heat release and local equivalence ratio in two-dimensional combustors is discussed. This technique uses a system of three CCD cameras and band-pass filters to collect light intensity in specific wavelengths characteristic of hydrocarbon flame chemiluminescence. Two of the cameras are monochromatic and are equipped with band-pass filters to collect light intensity in wavelengths containing C_2* (503 ＜ λ ＜ 519 nm) and CH* (422 ＜ λ ＜432 nm) chemiluminescence, respectively. The third camera is a color camera equipped with two triple-band pass filters to collect flame emission in three specific narrow bands for subtraction of background radiation (due to CO_2* broadband emission and thermal emission) from the CH* and C_2* images. Examples of chemiluminescence images obtained from a liquid-fuelled, bluff body-stabilized combustor will be presented and discussed.