Studies of Low Temperature Chemistry on Flame Instabilities

Numerical simulation on the incompressible N-S equation was completed to study the low temperature chemistry on flame instabilities by using the detailed chemical kinetics and transport property. The results show that the flame disturbance growth rate of the mixed gas involving low temperature chemistry (LTC) is significantly greater than that without LTC. By the analysis of the key parameters of the preheated mixed gas flame, it is found that the dimensionless heat release, Lewis number and Zeldovich number are significantly reduced compared with that of the flame without preheating. On the basis of the existing theory that the reduction of the above parameters makes the cellular instability decreased inhibitory effect on the growth of disturbances as Lewis number greater than 1. As a result, the growth rate of flame is obviously increased after preheating. At the same time, a large number of free radicals and other small molecules are formed in the low temperature reaction, which makes the flame Lewis number of the preheated mixture reduced, and the depth and height of the flame cellular structure become smaller.