Emission Spectroscopic Behavior fo Premixed Flames Near the Extinction Limit

点击翻译按钮获取中文摘要

It has been thought that the local extinction of turbulent premixed flames occurs due to the local flame stretch. However, the local extinction of turbulent premixed flames has never been observed experimentally because the definitive experimental technique to detect the local extinction has not been established. The objective of the present study is to establish the definitive experimental technique to detect the local extinction of turbulent premixed flames by measuring emissions of intermediate species from hydrocarbon-air premixed flames. Emission intensities of OH, CH, and C_2, the major intermediate species of the hydrocarbon-air flames, have been examined. It has been shown that the unique relation exists between flame temperature and the ratio of the emission intensities of the C_2 470nm and 515nm bands, implying that the flame temperature can be estimated by measuring the ratio of the emission intensities of the C_2 470nm and 515nm bands.