非稳态燃烧过程中泡沫陶瓷胞元结构对多孔介质燃烧器内热-力分布行为的影响

The porous media combustion (PMC) technology is a new combustion technology with advantages of higher combustion efficiency and less pollutants emission. The open-cell porous ceramic is one of the key components used in the PMC. The development and design of long-life open-cell porous ceramic materials are urgent needs for PMC engineering applications. Despite the specific material and crystal structure, the optimal cell structure of the porous ceramic is the fundamental way to improve the thermal shock resistance. This research aims to: 1. develop the three-dimensional microstructure model based on the morphology features together with the minimization of surface area per unit volume principle; 2. investigate the inner relationship between the cell structure and the mechanical performances by the extended finite element analysis technology; 3. establish the coupling combustion, fluid flow and heat transfer model within microstructure, and analyze the effect of the cell structure on the heat/mass transfer characteristics based on the reverse solving technology, furthermore, develop the unstable PMC model to simulate the temperature distribution; 4. finally, study the influence of the cell structures on the transient stress distribution in the porous ceramic based on the classical thermoelasticity theory and experiment results. The research will be an important reference for the porous ceramic material design and structure optimization.

多孔介质燃烧技术是一项绿色、高效的燃烧技术，开孔泡沫陶瓷是多孔介质燃烧技术的关键部件，开发和设计长寿命泡沫陶瓷材料是多孔介质燃烧技术工程应用的迫切需要。在材质和晶相组织已定前提下，泡沫陶瓷的胞元结构是影响其服役过程热-力分布的根本因素。本项目拟首先研究泡沫陶瓷胞元形貌特征，结合单位体积表面积最小化原则，数学重构泡沫陶瓷三维胞元结构模型；在胞元模型基础上，运用非连续有限元技术研究胞元结构与力学性能的内在关联；同时建立胞元尺度上的传热、传质与燃烧多场数学模型，运用反向求解技术研究胞元结构与泡沫陶瓷传热/传质特性的内在关联，进而基于传热/传质特性参数，构建宏观尺度上泡沫陶瓷内非稳态燃烧模型，求解温度场分布；最后结合经典热弹性理论与实验，分析非稳定燃烧条件下泡沫陶瓷内瞬时力场分布，从而探明非稳态燃烧条件下胞元结构对泡沫陶瓷内热-力分布行为的耦合影响机制。

多孔介质燃烧技术是一项绿色、高效的燃烧技术，开孔泡沫陶瓷是多孔介质燃烧技术的关键部件，开发和设计长寿命泡沫陶瓷材料是多孔介质燃烧技术工程应用的迫切需要。在材质和晶相组织已定前提下，泡沫陶瓷的胞元结构是影响其服役寿命的根本因素。本研究首先研究了泡沫陶瓷胞元形貌特征，结合单位体积表面积最小化原则，数学重构了泡沫陶瓷三维胞元结构模型；在胞元模型基础上，运用数值分析结合实验研究了胞元结构与多孔介质孔隙率、比表面积等之间的关联，进一步通过数值实验建立孔隙率、比表面等与多孔介质导热系数，辐射衰减系数以及综合有效导热系数之间的关联，获得多孔介质微观结构与宏观热物性参数之间的关联式。最后，利用3D打印技术，获得有序排列胞元结构的多孔介质，通过实验结合数值模拟，研究非稳态燃烧条件下多孔介质内瞬时温度分布，探明胞元结构参数对多孔介质内热力耦合行为的影响规律；通过胞元结构多参数优化分析，构建基于胞元结构参数的泡沫陶瓷抗热冲击评估模型。