火花点火发动机燃烧室内温度场的实验研究

在实际点火发动机上，利用激光剪切法结合高速摄影，测取了大量燃烧室内干涉条纹图，获取了缸内燃烧的二维温度场，并估算出火焰传播速度。从温度场可以看出，燃烧过程中缸内大致可分3个区：已燃区、未燃区和燃烧区。燃烧区温度最高，温度梯度大；已燃区温度次之，梯度较小；未燃区温度最低，但梯度较大。燃烧过程中，缸内的火焰面以近似球面向未燃区推进，火焰传播速度开始较小，随着燃烧的进行，迅速增大，达到一最大值后，逐渐减小，直至燃遍整个燃烧室。

Study on the Temperature Field of Engine Combustion Chamber in Spark Ignition Engines

A set of shearing-interferometry and high speed photography experimental facility, which is suitable for studying combustion,has been established successfully.The experimental results show that the application of laser shearing-interferometry for studying engine combustion is successful.The temperature field of engine combustion chamber can be measured quantitatively by image processing.And the flame propagation velocity can be calculated through it.In the process of combustion,the temperature in the burned area is higher than that in the unburned area.The temperature in the burning area is highest and the temperature gradient is steepest also.At the Inital Period of combustion,the flame propagation velocity is low.With the combustion going on,the velocity increases quickly.After a maximum velocity,it slows down.