使用定容燃烧弹与高速纹影照相系统研究了不同当量比下甲烷－空气预混气体的层流火焰燃烧特性。实验数据同时应用传统线性模型和非线性模型分析了不同当量比对球形扩展火焰的传播速率和马克斯坦长度的影响。结果显示：随着当量比的增加，层流燃烧速率先增大后减小，直到当量比为1．1时，火焰速率达到最大值。马克斯坦长度始终为正值，且随着当量比的增大而增大。在所有当量比条件下，线性和非线性方法计算的火焰速率大致相同，差值小于0．01 m／s；线性方法得到的马克斯坦长度均大于非线性模型计算的结果，并随着当量比的增大，两种方法得到的马克斯坦长度的差值更加显著。%An experimental study is performed in a constant volume vessel by using the schlieren system to investigate the laminar burning velocities and Markstein lengths of the premixed methane -air flame under different equivalence ratio and both the linear method and the nonlinear method are used to obtain the laminar burning velocity and Markstein length of an outwardly propagating spherical flame .Experiment results show that with the increase of equivalence ratio ,unstreched burn-ing velocity firstly increases and then reduces ,and laminar burning velocity reaches their maximum values at the equivalence ratio of 1 .1 .Markstein length is always positive and increases with the increase of equivalence ratio .Comparison shows that the difference of the burning velocity obtained by using different stretch models is less 0 .01 m/s .Markstein lengths by using linear method are generally higher than those from nonlinear analysis .With the increase of equivalence ratio ,the difference of the Markstein lengths obtained by different analysis methods becomes even more significant .
展开▼
