亚毫米空间内火焰从层流向爆燃模式的转变特性研究

为了探究微小空间内的火焰加速特性,在一个可视化的、特征间距为0.45mm的微尺度定容燃烧室内,实验研究了丙烷/氢气/空气预混的火焰传播特性。实验考察了亚毫米空间条件下掺氢比例、混合气初始温度和初始压力对火焰传播的影响,其中掺氢比例分别为0.2和0.4,初始温度分别为290K和306K,初始压力从0.1MPa到0.3MPa。实验观察到了火焰在传播过程中加速,并发生缓燃转变到爆燃的现象,火焰传播速度获得大幅提升。另外发现初始压力的提升有利于加速火焰传播,提升峰值压力,且较小幅度的初始温度上升能够有效提高火焰传播速度。

Characteristics of Flame Transition from Laminar to Deflagration in a Sub-Millimeter Space

In order to explore the characteristics of flame acceleration in a micro space, the experimental study on propane/hydrogen/air mixture combustion was carried out in a visualized micro-scale constant volume combustion chamber. The combustion chamber has a characteristic spacing of H=0.45 mm. The flame propagation of propane/hydrogen mixture was compared with different initial pressures (1.25 atm to 3.0 atm) hydrogen ratio (0.2 and 0.4) and initial temperature (290 K and 306 K). The experimental results showed that the flame accelerates during the propagation process, and the transition from laminar to deflagration occurs, leading to significant increase of the flame propagation speed. In addition, the increase of the initial pressure is beneficial to the acceleration of flame propagation speed and the increase of the peak pressure. A small initial temperature rise can greatly increase the flame propagation speed.