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自然界和工程领域中的许多物理现象的发生通常涵盖几个数量级的几何空间及时间范围,我们将其统称为多尺度物理现象.在模拟多尺度问题时,如果仅采用宏观方法,则会存在一些不足,如无法预知微小部分的细节以及引入复杂的经验关联式;如果仅采用介观/微观方法,则需要消耗大量的计算资源.构造宏观-介观、宏观-微观、宏观-介观-微观等多种层次上方法的耦合体系,可以在很大程度上克服这些不足.构造了宏观有限容积法(FVM)与介观格子Boltzmann方法(LBM)的耦合模型(CFVLBM),给出了由宏观物理量重构密度分布函数和温度分布函数的两个重构算子,解决了LBM与宏观方法耦合的关键难题.选取二维、三维典型传热流动问题对耦合模型进行了考核,计算结果同基准解符合得很好.最后将CFVLBM应用于计算多孔介质内的复杂流动问题.研究表明,基于文中重构算子的CFVLBM可以准确有效地应用于模拟传热流动问题.
The occurrence of many physical phenomena in nature and in engineering often covers geometries and time ranges of several orders of magnitude, which we collectively refer to as multi-scale physical phenomena. When modeling multi-scale problems, only macroscopic approaches exist Insufficient, such as unpredictable details and the introduction of complex empirical correlations, require large computational resources if only mesoscopic / microscopic methods are used Constructs macroscopic - macroscopic - microcosmic - macroscopic - mesoscopic - microscopic And other hierarchical coupling methods can largely overcome these shortcomings.The coupled model (CFVLBM) of macroscopic finite volume method (FVM) and mesoscopic lattice Boltzmann method (LBM) is constructed, The two reconstruction operators of density reconstruction function and temperature distribution function are used to solve the key problem of the coupling between LBM and macroscopical method.The two-dimensional and three-dimensional heat transfer flow problems are used to evaluate the coupling model, The solution is in good agreement.Finally, CFVLBM is applied to the calculation of complex flow problems in porous media.Research shows that the CFVLBM based on the reconstruction operator in the text can be quasi It is effectively applied to simulate heat transfer problems.