Study on Flame Dynamics of Premixed Flames with Controlled Curvature by Laser Irradiation Method

采用外部激光辐照的方法，研究了给定初始曲率的预混火焰的火焰不稳定性。首先将该方法应用于平口火焰燃烧器，实验揭示了刘易斯数(Le)对弯曲火焰生长速度的影响。随着Le的降低，生长速度明显变大。在传播管实验中，研究了声场与弯曲火焰的相互作用。作为研究的结果，本文重新定义了无量纲数--脉动弗劳德数，并得出结论：无量纲数可以给出声场自湍动的判据。

Evolution of flame instability of premixed flame with a given initial curvature by external laser irradiation method was investigated. At first the method was applied to open flat flame burner and the effect of Lewis number (Le) on the growth rate of curved flame was experimentally revealed. The growth rate was apparently larger with lower Le. In experiments with propagation tube, the interaction between acoustic field and curved flame was investigated. As a result of the investigation, non-dimensional number, Pulsating Froude Number, Gp, was newly defined in the present work and it was concluded that the criterion of self-turbulization in acoustic field could be given by the non-dimensional number.