多相反应流的数值模拟方法

发布时间：2018-04-18 17:17

本文选题：流体动力学 + 多相流　；参考：《中国工程物理研究院》2016年博士论文

【摘要】：多相反应流的数值模拟在许多应用研究领域发挥着重要的作用,例如在武器弹药设计与毁伤评估,重大爆炸灾害的防灾减灾,高速推进器技术以及天体物理中的超新星爆发等国防,民用和科学研究中都是不可或缺的研究手段.本文主要研究多相反应流的数值模拟方法.多相反应流指含有化学反应的多相流,不同相对应的状态参数不同.本文首先从数值格式,边界处理,网格技术和边界处理等多个方面,综述了微分方程数值模拟与爆轰史上的重要进展和发展变化,特别是多相反应流的历史发展.对爆轰的经典理论,如Chapman-Jouguet(CJ)模型和Zeldovich-von Neumann-Doring(ZN D)模型作了比较详细的论述,介绍了爆轰过程从瞬间反应到区分前导激波和反应区,再到二维多波相互作用而产生的胞格现象的整个过程.对于理想流体,本文利用Godunov格式,结合Harten-Lax-Leer-Contact (HLLC)类型的Riemann求解器,构造了相应的数值方法,并应用到一维和二维理想爆轰问题的数值模拟,包括稳态的与非稳态爆轰问题.数值模拟结果表明,这种算法鲁棒性好,能够有效捕捉爆轰波的结构特征.同时研究了高精度的移动网格数值方法在爆轰流体中的应用,比较了他们与广义黎曼问题(GRP)方法在数值精度方面的差异.对于非理想流体,本文主要考虑了三种不同类型的状态方程：刚性状态方程,Cochran-Chan(CC)状态方程和Jones-Wilkins-Lee(JWL)状态方程.针对这些非理想反应流,由于欧拉方法数值模拟中,会出现不同相的混合单元,本文发展了一种物理量重构法.应用单元格内不同物质的物理量之间的关系,如混合密度与各自密度之间的关系,以及混合内能与各物质内能之间的关系,根据热力学平衡条件,建立了多个未知变量的方程组.通过求解这个方程组,重构出混合单元内的各相物理量,结合前述的HLLC求解器,计算出单元界面的数值通量.在求解方程组时,由于相应的代数方程的多解,给数值方法带来一定的困难,本文提出一种“移动跟踪法”,能够快速得到具有物理意义的解.本文将上述算法应用到多相流的数值模拟中,给出了大量的一维和二维算例.数值结果表明,这种算法既能清晰地捕捉一维和二维的爆轰波的结构,又能比较准确地捕获多波的相互作用,得到的胞格边界清楚,排列有序,三波点的特征明显.这些都验证了该算法的有效性和可靠性.作为论文的结尾,总结讨论了这些算法的特点,并展望了下一步的工作可能遇到的困难和问题.
[Abstract]:Numerical simulation of multiphase reaction flows plays an important role in many applied research areas, such as weapons and ammunition design and damage assessment, disaster prevention and mitigation of major explosive disasters,High-speed thruster technology and supernova explosion in astrophysics are indispensable for national defense, civil and scientific research.In this paper, the numerical simulation method of multiphase reaction flow is studied.Multiphase reaction flow refers to a multiphase flow containing chemical reactions with different state parameters.In this paper, the important progress and changes in numerical simulation of differential equations and detonation history, especially the history of multiphase reaction flow, are reviewed in terms of numerical scheme, boundary treatment, grid technology and boundary treatment.The classical theories of detonation, such as Chapman-Jouguett CJ model and Zeldovich-von Neumann-Doring(ZN Dmodel, are discussed in detail, and the whole process of detonation process from instantaneous reaction to distinguishing leading shock and reaction region to two-dimensional multiwave interaction is introduced.For the ideal fluid, the corresponding numerical method is constructed by using the Godunov scheme and the Riemann solver of Harten-Lax-Leer-Contact / HLLC type, and applied to the numerical simulation of one-dimensional and two-dimensional ideal detonation problems, including steady and unsteady detonation problems.The numerical simulation results show that the proposed algorithm is robust and can capture the structural characteristics of detonation waves effectively.At the same time, the application of high precision moving grid numerical method in detonation fluid is studied, and the difference between them and the generalized Riemannian problem (GRP) method in numerical accuracy is compared.For nonideal fluids, three different types of state equations are considered in this paper: the rigid state equation (Cochran-Chann CCS) and the Jones-Wilkins-Leewe (JWL) equation of state.For these non-ideal reaction flows, due to the existence of mixed elements with different phases in the numerical simulation of Euler's method, a physical quantity reconstruction method is developed in this paper.Based on the thermodynamic equilibrium conditions, the relationship between the physical quantities of different substances in a cell, such as the relation between the mixing density and the respective density, and the relationship between the mixed internal energy and the internal energy of each substance, is applied.The equations of several unknown variables are established.By solving the equations, the physical quantities of each phase in the mixed element are reconstructed, and the numerical flux of the interface of the unit is calculated by combining the HLLC solver mentioned above.In solving the equations, it is difficult to solve the numerical method because of the multiple solutions of the corresponding algebraic equations. In this paper, a "moving tracking method" is proposed, which can quickly obtain the solution with physical significance.In this paper, the algorithm is applied to the numerical simulation of multiphase flow, and a large number of one-dimensional and two-dimensional numerical examples are given.The numerical results show that this algorithm can capture the structure of one-dimensional and two-dimensional detonation waves clearly and accurately capture the interaction of multiple waves. The results show that the lattice boundary is clear, the arrangement is ordered, and the characteristics of the three wave points are obvious.These results demonstrate the validity and reliability of the algorithm.At the end of the paper, the characteristics of these algorithms are summarized and discussed, and the difficulties and problems that may be encountered in the next work are prospected.
【学位授予单位】：中国工程物理研究院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O241.82

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