Abstract
This paper presents both experimental and numerical studies to investigate the impact of ozone concentration on a methane/air mixture combustion process. The experiments were conducted in a constant-volume combustion bomb at elevated initial pressures. Combustion pressure history, combustion duration, and burning rate were obtained at different air/fuel ratios, initial pressures, and ozone mixing ratios. The results suggested that ozone addition promoted combustion by increasing peak pressure and peak burning rate and decreasing combustion duration. Chemical kinetic calculation was carried out to assist in the understanding of how ozone enhanced the combustion process. The calculation results revealed that the dominant production and consumption reactions were enhanced by ozone addition. The promotion effect of ozone on the combustion process was mainly caused by the O atom decomposed from ozone. With ozone addition, the concentration of O, H, OH, and HO₂ increased more obviously in the early stage of the combustion process, and ozone mainly played an important role at the beginning of the mixture oxidation.