Hydrodynamic and thermal mechanisms of filtration combustion inclinational instability based on non-uniform distribution of initial preheating temperature

2017 International Symposium on Application of Materials Science and Energy Materials

材料科学;能源学

Xia, Yongfang^1 ; Shi, Junrui^1 ; Xu, Youning^1 ; Ma, Rui^1

Key Lab. of Clean Combust. for Elec. Generation and Heat-supply Technology of Liaoning Province, Shenyang Institute of Engineering, Shenyang, China^1

关键词: Combustion systems;    Equivalence ratios;    Filtration combustion;    Non-uniform distribution;    Porous media combustions;    Preheating temperature;    Quasi-steady conditions;    Thermal mechanisms;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/322/7/072022/pdf
DOI  :  10.1088/1757-899X/322/7/072022

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Filtration combustion (FC) is one style of porous media combustion with inert matrix, in which the combustion wave front propagates, only downstream or reciprocally. In this paper, we investigate the FC flame front inclinational instability of lean methane/air mixtures flowing through a packed bed as a combustion wave front perturbation of the initial preheating temperature non-uniformity is assumed. The predicted results show that the growth rate of the flame front inclinational angle is proportional to the magnitude of the initial preheating temperature difference. Additionally, depending on gas inlet gas velocity and equivalence ratio, it is demonstrated that increase of gas inlet gas velocity accelerates the FC wave front deformation, and the inclinational instability evolves faster at lower equivalence ratio. The development of the flame front inclinational angle may be regarded as a two-staged evolution, which includes rapid increase, and approaching maximum value of inclinational angle due to the quasi-steady condition of the combustion system. The hydrodynamic and thermal mechanisms of the FC inclinational instability are analyzed. Consequently, the local propagation velocity of the FC wave front is non-uniform to result in the development of inclinational angle at the first stage of rapid increase.