Lean combustion can greatly improve the thermal efficiency of gasoline engine. Increasing ignition energy and tumble level can effectively expand its application range. Optical glass liner was used to clearly observe the in-cylinder state. Particle image velocimetry(PIV) was used for quantitative evaluation of tumble modification. The integral tumble ratio of the high tumble intake port is 1.67 times that of the basic intake port. Ignition energy was increased from 65 mJ to 300 mJ. Under the condition of no fuel injection, the duration of 300 mJ ignition arc is longer, and the peak arc area is about 4 times that of 65 mJ. The effects of ignition energy and tumble level on combustion stability, lean-burn limit, fuel economy and flame development were studied. The results show that high energy ignition can enlarge the lean-burn limit, but has no significant effect on combustion stability. High tumble has the opposite effect and can effectively improve fuel economy. The micro flame development images under the ultra-lean condition are different. The flame area of 300 mJ is larger and the combustion is more intense. High energy ignition contributes to the formation of initial flame kernel and flame propagation, so it can improve the lean-burn limit.

稀薄燃烧可以大大提高汽油机的热效率。提高点火能量和翻滚水平可以有效扩大其应用范围。光学玻璃衬管用于清楚地观察缸内状态。粒子图像测速法(PIV)用于对翻滚改性的定量评价。高滚流进气道的整体滚流比是基本进气道的 1.67 倍。点火能量从 65 mJ 增加到 300 mJ。在不喷油情况下，300mJ点火电弧持续时间较长，峰值电弧面积约为65mJ的4倍。研究了点火能量和翻滚水平对燃烧稳定性、稀燃极限、燃料经济性和火焰发展的影响。结果表明，高能点火可以扩大稀薄燃烧极限，但对燃烧稳定性无显着影响。高翻滚作用相反，可有效提高燃油经济性。超稀薄条件下的微火焰发展图像不同。300mJ的火焰面积更大，燃烧更剧烈。高能点火有助于初始火焰核的形成和火焰传播，因此可以提高稀薄燃烧极限。