Oxygen concentration distribution measurement of the nozzle flow field by toluene/acetone Planar Laser Induced Fluorescence

Planar laser-induced fluorescence (PLIF) of toluene and acetone is performed for visualization of spatial distribution of oxygen in gas and oxygen mixing region in the nozzle flow field. The principle of the calibration methods of oxygen concentration distribution is expounded in this paper. As the two tracers had different situations on oxygen quenching effect, the ratio of the fluorescence images of the two tracers could be used to measure the oxygen concentration in the mixed area. In this way, the ratio of fluorescence signal intensity of toluene to acetone was found to be linearly related to oxygen concentration. By using this calibration relationship, we can measure the oxygen concentration distribution of the nozzle flow field with an accuracy of 12.6%. It indicates that this measurement method can be applied in a turbulent flow field. The variation trend of oxygen concentration distribution in the nozzle flow field can be analyzed by capturing multiple PLIF images in time sequence, which has the important reference value for the development of the nozzle burner flame.