楔形障碍物与火焰的作用

Interaction Between the Wedge Obstacle and Flame

采用多镜头Cranz&Schardin高速摄影机,对卧式燃烧方管内楔形障碍物与CH4/空气预混火焰的相互作用进行了实验研究,获得了高清淅度的障碍物诱导火焰失稳的分幅时序照片。基于RANS方法,对上述复杂物理现象进行了数值模拟。计算结果与实验结果基本相符,反映了火焰在管内传播与变形的详细过程,得到了楔形障碍物所导致的火焰加速与变形的内在机理,揭示了火焰传播过程中由层流燃烧向湍流燃烧转捩的本质。

Experimental investigations have been performed in a horizontal rectangle tube on the interactions between a wedge obstacle and premixed flame of CH4/Air mixture using the Cranz ＆ Schardin high speed camera system. Sequences of high-speed images with high resolution showing the process of a flame instability under the action of the wedge obstacle have been obtained. Besides, based on RANS method, a numerical calculation has been carried for simulating the above complex physical phenomenon. Both experimental and numerical results are in good agree- ment. These results show the inherent mechanism of flame acceleration and its front distortion, as well as the nature of a transition from laminar combustion to turbulence during its propagation.