Study of OH Radicals’ Spontaneous Radiation of Counterflow Diffusion Flame under Non-equilibrium Plasma

摘要

Plasma assisting technique has shown great prospect in various combustion environments. Especially interrible combustion problems, plasma brings heat effects, chemical kinetic effects, or transport effects to influencecombustion. Fundamental research of non-equilibrium plasma assisting combustion is prerequisite for itsengineering application. Counterflow burner provides an ideal and favourable platform to investigateaforementioned problems. This article integrated non-equilibrium plasma discharge system and counterflow burnerto investigate influence of coaxial double air gap dielectric barrier discharge on counterflow diffusion flame. OHradicals generation and radiation were observed to reveal basic chemical kinetic mechanisms of plasma. Ultravioletintensified ICCD camera was used to record OH radicals' spontaneous radiation in flame sheet. Radiation imagesshow that plasma discharge would increase intensity of OH radicals' radiation and combustion of flat flame whendischarge voltage was under certain value; when discharge voltage exceeded the certain value, airflow in burnerwould be inevitably affected by discharge, and uniformity of OH radicals' radiation declined, while in thecentral zone, flow speed increased, thermal loss decreased and combustion-assistant effects weakened.