Study on concentration distribution of radical groups of gasoline-air explosion in long-narrow confined space based on OH-PLIF

To measure the key free radicals of the gasoline-air explosion in long-narrow confined space accurately, which is important to the accurate analysis of the explosion flow field and the flame propagation, an experimental study on the gasoline-air mixture explosion in a long-narrow confined space is designed based on the planar laser induced fluorescence system (PLIF),and the experiments in different conditions of the gasoline-air explosion in long-narrow confined space are carried out. The concentration distributions of the OH radical of those are obtained. The results of experiments show that the concentration of OH radical rises and then descends among the gasoline concentrations of 1.1%—2.4%(volume fraction); the concentration of OH radical rises steadily along with the development of flame propagation, which means the explosion is strengthen; the distributions of the OH radical are different in different explosion stages, which means the combustion reaction area in different explosion stages differs a lot; there is a "isolation belt" between the flame and the wall, which is the result of the slowing of the flame propagation caused by the concentration increase of unburned gasoline. The main innovation is to solve the transient measurement of free radical distribution in unsteady premixed combustion by designing the timing control subsystem.