湍流射流点火燃烧特性的模拟研究

稀薄燃烧策略可以在提高燃料效率的同时减少污染物排放,而预燃室式湍流射流点火技术作为一种强点火方式能够有效提高燃烧稳定性.采用数值模拟手段对稀薄混合气湍流射流点火燃烧特性进行研究.结果 表明:在混合气过量空气系数(φa)为1.5的情况下,湍流射流点火相较传统火花塞点火最高燃烧压力提高66.4％,NOx排放相较当量比燃烧降...

Simulation on Combustion Characteristics of Turbulent Jet Ignition

The lean combustion strategy can improve fuel efficiency and also reduce pollutant emission.As a forced ignition method,the pre-combustion chamber turbulent jet ignition technology can effectively improve combustion stability.The combustion characteristics of turbulent jet ignition in lean mixtures were studied by using numerical simulation.The results show that the maximum combustion pressure of turbulent jet ignition is 66.4%higher than that of traditional spark plug ignition,and the NO_xemission is 93.9%lower than that of equivalence ratio combustion when the excess air ratio(?a)of mixture is 1.5.Increasing the auxiliary fuel of the pre-combustion chamber can increase the initial kinetic energy of hot jet and improve the jet flame structure to accelerate the consumption rate of mixture in the main combustion chamber.In the turbulent jet ignition mode,the turbulent kinetic energy of main combustion chamber has two peaks,and the increase of turbulent kinetic energy promotes combustion.