Combustion of a porous solid fuel is considered. An exothermic reaction takes place between the fuel and a gaseous oxidiser which is delivered to the reaction zone by filtration through the pores in the sample from an open end toward which the combustion wave propagates (counterflow filtration). The gas reacts with the solid fuel to form a solid product. The gas filtration is due to the pressure difference between the ambient pressure at the open end and the pressure in the reaction zone where the gas is being consumed (referred to as natural filtration). A 1D mathematical model based on equations describing conservation of energy, gas mass, solid reactant mass, and gas momentum, as well as an equation of state, and appropriate boundary and initial conditions is formulated and analytically studied taking advantage of the separation of length scales in the process. When the reaction zone is sufficiently far from the open end, the combustion wave propagates at a constant speed and has a time-independent structure, while when the reaction is close to the open end (closer than the filtration length), the structure of the combustion wave and its speed become time dependent. Both cases are discussed in the paper though the main emphasis is on short samples, in which the combustion wave is affected by the gas flow from the open end during the entire propagation process. A specific example of interest involves magnesium as the solid fuel and oxygen as the gaseous oxidiser.

考虑了多孔固体燃料的燃烧。燃料和气体氧化剂之间发生放热反应，气体氧化剂通过从燃烧波传播的开口端通过样品中的孔过滤（逆流过滤）而输送到反应区。气体与固体燃料反应形成固体产物。气体过滤是由于开口端的环境压力与消耗气体的反应区压力之间的压力差（称为自然过滤）。基于描述能量守恒、气体质量、固体反应物质量和气体动量的方程以及状态方程的一维数学模型，并利用过程中长度尺度的分离来制定和分析研究适当的边界和初始条件。当反应区离开口端足够远时，燃烧波以恒定的速度传播，并具有与时间无关的结构，而当反应区靠近开口端（比过滤长度更近）时，燃烧波的结构为燃烧波及其速度与时间有关。本文讨论了这两种情况，但主要强调的是短样本，其中燃烧波在整个传播过程中受到来自开口端的气流的影响。一个感兴趣的具体例子涉及作为固体燃料的镁和作为气态氧化剂的氧。燃烧波以恒定速度传播并具有与时间无关的结构，而当反应接近开口端（比过滤长度更近）时，燃烧波的结构及其速度变得与时间有关。本文讨论了这两种情况，但主要强调的是短样本，其中燃烧波在整个传播过程中受到来自开口端的气流的影响。一个感兴趣的具体例子涉及作为固体燃料的镁和作为气态氧化剂的氧。燃烧波以恒定速度传播并具有与时间无关的结构，而当反应接近开口端（比过滤长度更近）时，燃烧波的结构及其速度变得与时间有关。本文讨论了这两种情况，但主要强调的是短样本，其中燃烧波在整个传播过程中受到来自开口端的气流的影响。一个感兴趣的具体例子涉及作为固体燃料的镁和作为气态氧化剂的氧。本文讨论了这两种情况，但主要强调的是短样本，其中燃烧波在整个传播过程中受到来自开口端的气流的影响。一个感兴趣的具体例子涉及作为固体燃料的镁和作为气态氧化剂的氧。本文讨论了这两种情况，但主要强调的是短样本，其中燃烧波在整个传播过程中受到来自开口端的气流的影响。一个感兴趣的具体例子涉及作为固体燃料的镁和作为气态氧化剂的氧。