Study on Combustion Characteristics of Gasoline in O2/CO2 Environment

Basing on Constant volume combustion bomb to simulate the combustion environment of gasoline direct injection (GDI) engine, the effects of initial oxygen concentration on the combustion characteristics and ame propagation characteristics of homogeneous combustion for gasoline in O2/CO2 nitrogen free environment were investigated. The results show that when the initial oxygen pressure is constant, with the increase of oxygen concentration (45%~60%), the peak pressure decreases slightly, but the peak pressure time is obviously ahead, the ame developing duration is shortened, and the combustion duration is shortened by nearly 3.2~3.5 times, the maximum heat release rate increases nearly 2.5 times, the pressure rise rate increases significantly, the combustion speed accelerates obviously, the fuel burn more vigorously. when the initial oxygen pressure is lower than 0.16 MPa, the knock can be ignored. With the increase of oxygen pressure and oxygen concentration, combustion knock intensity increased, reasonably choice of oxygen pressure and oxygen concentration can effectively inhibit the knock. © 2019, Science Press. All right reserved.