Experimental study of the combustion characteristic of circular transverse fuel jet in crossflow

Abstract

Experimental studies of the combustion process of circular transverse methane jets in crossflow are carried out both at stable combustion conditions and approaching flameout. It is found that under stable combustion, a steady recirculation zone is formed downstream of the jet, and the mixing coefficient is basically constant under different conditions. Thus, the excess air coefficient in the recirculation zone is also basically constant, and the combustion temperature and combustion efficiency almost don't change with the overall excess air coefficient, especially in the back half of the recirculation zone, within the experiment extent. Under stable combustion, high combustion efficiency is observed at a short distance downstream of the jet. When the flame approaches to extinguished, the recirculation zone cannot exist steady, resulting in a sharp increase of the excess air coefficient and a sharp decrease of the combustion temperature in the combustion zone. Approaching flameout, the flame oscillates distinctly, dissipates heat and energy during the oscillation process, then goes out.