基于格子Boltzmann方法的多孔介质孔隙特性的研究
文献类型：学位论文
| 作者 | 李莎 |
| 学位类别 | 硕士 |
| 答辩日期 | 2012-05-21 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 雍玉梅 ; 杨超 |
| 关键词 | 格子Boltzmann方法 多孔介质 微观结构 挠曲度 对流扩散 |
| 其他题名 | Study on Pore Characteristics of Porous Medium by Lattice Boltzmann Method |
| 学位专业 | 化学工程 |
| 中文摘要 | 多孔介质内的对流扩散现象一直以来都是人们研究的重要问题。影响多孔介质传递性质的因素很多，如多孔介质的微观结构、孔隙率、渗透率和挠曲度等，对这些参数的研究不仅有其理论价值，而且有直接的应用价值。由于多孔介质的结构非常复杂，迄今对这些参数性质的认识还不够准确、全面。因此需要用更加有效的方法对表示多孔介质的孔隙特性、输运性质的参数进行深入的研究和探索。格子Boltzmann方法是基于流体微观模型和介观动理学模型的一种方法，对于介观尺度的研究具有独特的优势。本文应用格子Boltzmann方法模拟了多孔介质内气体的扩散过程，研究了孔隙特性对多孔介质内气体扩散的影响，包括孔隙结构、通道直径和润滑圆角这些孔隙特性对扩散过程的影响。这些探索为多孔介质的构造和微反应器孔隙特性的设计和优化提供了依据和数据支持挠曲度是多孔介质的重要物理参数，与孔隙度有直接关系，本文对不同孔隙率下多孔介质的挠曲度进行了研究。应用格子Boltzmann方法计算得到不同孔隙率下的挠曲度，与实验值和经验公式计算值比较，吻合很好。根据模拟值拟合得到更适合本文所产生的这种多边形棋盘式多孔介质的经验公式。本文还根据格子Boltzmann方法的双组份的多松弛（MRT）模型建立了双组份的对流扩散程序，并用Poiseuille流动验证程序，模拟结果与解析解非常吻合。对双组份的扩散进行模拟，与文献结果吻合良好，充分验证了双组份MRT模型的正确和有效性，为今后研究不同分子量的两组份传质打下基础。 |
| 英文摘要 | The research on convection and diffusion phenomenon in porous media is an important region in chemical engineering field. Various factors will influence the transfer properties of porous media, such as the pore structures, porosity, permeability, tortuosity and so on. Studying these factors has great importance not only in theory but also in engineering application. However, the complexity of pore structures hinders profound, comprehensive recognition of these parameters, so a more effective method needs to be applied to further investigate the pore characteristics and transfer properties. Lattice Boltzmann method is based on the microscopic model or mesoscopic kinetics equations and has unique advantages in handling mesoscopic problems. In this thesis the gas diffusion process in porous media is simulated to investigate the effects of pore characteristics on the diffusion process, such as pore structures, width of channels and radii of filleted corners. These explorations provide both theoretical bases and statistical support for the generation of porous media and the design and optimization of the pore characteristics of micro-reactors. Tortuosity is an important physics factor for porous media, and related with porosity directly. In this thesis the relation of tortuosity and porosity is studied. The tortuosities acquired by lattice Boltzmann method agree well with experimental data and empirical expressions. According to these numerical simulation results, an empirical relation more which is suitable for capillary tube model of porous media generated in this thesis is proposed. In this thesis, the advection and diffusion code for binary mixtures based on the Multi-relaxation-time(MRT) lattice Boltzmann model for binary mixtures is built. Poiseuille flow is used to test the code and the result is very good. The diffusion process of binary mixtures is simulated by this code, and the results of present work agree well with the published results in the literature. These tests qualify the MRT model for binary mixtures and this code, and lay a solid foundation for the transport research of binary mixtures with different molecular weights. |
| 语种 | 中文 |
| 公开日期 | 2013-09-25 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1854]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 李莎. 基于格子Boltzmann方法的多孔介质孔隙特性的研究[D]. 中国科学院研究生院. 2012. |
入库方式： OAI收割
来源：过程工程研究所
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