Novel design of one-layer porous burner for experimental studies of the flame front dynamics at pore scale level is proposed. Results of the experimental and numerical studies of non-stationary flame front behavior at pore scale are discussed and compared at a qualitative level. The results demonstrate that upstream propagation of the combustion wave can be accompanied by the oscillations of two different types. The first type is the FREI-like pulsations, which mechanism is identical to the flames with repetitive extinction and ignition in narrow channels with external heating. The second type is the small-amplitude oscillations, which, apparently, have the same nature as the transitional oscillatory combustion mode between the steady flame and fully-developed FREI pulsations. This type of unstable flame behavior differs by existing of the flame over the entire oscillation period without extinction. It is found that these two types of flame oscillations clearly separates by oscillation frequencies and amplitudes. Typical frequencies of FREI-like pulsations are about tens of hertz, while for small amplitude oscillations it has an order of hundreds of hertz. It was shown that both types of oscillations can coexist inside the porous media at the same time but at different pore channels. Moreover, the mixed oscillations representing by fully developed FREI-like pulsations alternating with small-amplitude oscillations are frequently observed.

提出了用于在孔隙尺度水平进行火焰前缘动力学实验研究的单层多孔燃烧器的新设计。在定性水平上讨论和比较了孔隙尺度非平稳火焰前沿行为的实验和数值研究结果。结果表明，燃烧波的上游传播可以伴随两种不同类型的振荡。第一种是类FREI脉动，其机制与火焰在外部加热的狭窄通道中重复熄灭和点火相同。第二种是小振幅振荡，显然与稳定火焰和完全发展的 FREI 脉动之间的过渡振荡燃烧模式具有相同的性质。这种不稳定的火焰行为的不同之处在于火焰在整个振荡周期内存在而没有熄灭。发现这两种类型的火焰振荡在振荡频率和振幅上明显分开。FREI 类脉动的典型频率约为数十赫兹，而对于小振幅振荡，它具有数百赫兹的数量级。结果表明，两种类型的振荡可以同时存在于多孔介质内部，但存在于不同的孔道中。此外，经常观察到由完全发展的类 FREI 脉动与小幅度振荡交替表示的混合振荡。FREI 类脉动的典型频率约为数十赫兹，而对于小振幅振荡，它具有数百赫兹的数量级。结果表明，两种类型的振荡可以同时存在于多孔介质内部，但存在于不同的孔道中。此外，经常观察到由完全发展的类 FREI 脉动与小幅度振荡交替表示的混合振荡。FREI 类脉动的典型频率约为数十赫兹，而对于小振幅振荡，它具有数百赫兹的数量级。结果表明，两种类型的振荡可以同时存在于多孔介质内部，但存在于不同的孔道中。此外，经常观察到由完全发展的类 FREI 脉动与小幅度振荡交替表示的混合振荡。