中文摘要：

考虑详细化学反应及输运过程,对不可压N-S方程直接数值求解,研究了低温化学影响下的火焰水力学及胞状不稳定性。结果表明,预热后已发生低温化学反应的混合气,其火焰的扰动增长率明显大于未发生低温反应的混合气火焰。通过对预热后混合气火焰的关键参数分析,发现和未预热混气火焰相比其无量纲释热量、Lewis数及Zeldovich数都显著减小。依据已有理论可知,在Lewis数大于1的条件下,上述参数的减小将使得胞状不稳定性对扰动增长的抑制作用减弱。因此,预热后火焰的增长率明显增大。同时,在低温反应中,大量自由基和其它小分子的形成,使得预热后混合气火焰Lewis数减小,从而其火焰胞状结构的深度和高度都变小。

英文摘要：

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.