光滑管中预混火焰传播物理机理的实验研究

开展了常温常压下二元燃料氢气/丙烷和空气预混气体在光滑方管道中火焰传播物理机理的实验研究。采用压力-时间记录法和纹影法两种测试方法,获得火焰传播速度和火焰阵面结构沿管道变化情况。结果表明:两种方法所测得的火焰传播速度在所测量范围内都先增加后减小。火焰加速传播机理主要是前方未燃气体受到前驱压缩波作用而被加热和压缩的正反馈微分加速机制,之后在管端反射的压缩波影响下,火焰传播速度略有降低。

An experimental study on physical mechanisms of the premixed flame propagation in a smooth square channel

An experimental study on physical mechanisms of flame propagation of premixed binary fuels hydrogen/propane/air mixtures is carried out in paper. All experiments are performed in a smooth square channel at normal pressure and temperature. With booth pressure transducer and high-speed camera technology, flame propagation velocity and front structure are obtained along the axis of channel. The main conclusions are: the flame propagation velocity originally increases and subsequently decreases within the measuring range. The positive-feedback differential loop resulted from the preheating and compressing unburnt mixtures ahead of flame by precursor shock, as mainly physical mechanisms, is responsible for flame propagation. Afterwards, the flame propagation velocity slightly decreases under the influence of compression waves reflected from the channel terminus.