离散流

The control volume integration was applied to deduce the discrete expressions of the convection-diffusion equations. The staggered grid and SIMPLE algorithm were introduced to deal with coupling between pressure and velocity, and then the numerical computation expressions of such variables as fluid flow velocity and pressure were deduced. Using the backward difference method and incremental theory to discretize the governing equations for fields of chemical reaction, material structure and chemorheology, the numerical computation expressions of variables such as the monomer conversion, average molecular weight and fluid viscosity were constructed.

应用控制容积积分法导出了对流—扩散方程的离散表达式，引入交错网格技术与SIMPLE算法，实现了耦合的压力场与速度场的分离式求解，推导得到了流体的流动速度、压力等物理量的数值计算式；采用向后差分方法和增量方法，实现了化学反应场、材料结构场、化学流变场控制方程的离散，获得了反应转化率、聚合物平均相对分子质量、流体黏度等物理量的数值计算式。

Those equations are dispersed in space by iso-parameter elementmethod and in time by using backward difference. A numerical simulator is established byFortran, the ideas of high part make the of structure program clear, maintain easy, calculationeffective.

在此基础上利用Fortran语言编制了有限元方法的油藏模拟器，采用等参元对渗流方程在空间上离散，采用向后差分在时间上离散，线性方程组的求解采用变带宽高斯消去法，该方法充分利用刚度矩阵呈条带状和其对称性的特点，大大减少了所需存储空间。

The application of the lattice Boltzmann method in unsteady open channel flows was studied in detail in the paper. An existing lattice BGK model was mended; For the problem of negative local equilibrium and evolutionary distribution, we proposed a lattice Boltzmann model based on cell-population equilibrium, which is a direct non-negative approximation to the continuous Maxwell distribution. The model reduces the transport and collision, two basic evolution steps in the LB model, to transport of the non-equilibrium distribution.

本文系统的研究了格子Boltzmann 方法在明渠非恒定流中的应用问题，改进了一个现有的LB 模型，数值实验表明此改进是有效的；在平衡态分布函数及分布函数的非负性问题上，作者提出了一个基于单元均衡的格子Boltzmann 模型，通过直接对Maxwell 分布函数的离散化实现对速度分布函数的非负离散，这种方法将传统模型演化过程中的碰撞和输运两个步骤直接表现为粒子的输运。

In this paper, a Robust Discrete Optimization model of elevator group control system is presented for dealing with the uncertainty in elevator traffic flow and computational complexity in scheduling. Based on RDO theory, we propose a new elevator group scheduling Algorithm. Comparison is carried between the RDO algorithm and other scheduling algorithms under the virtual simulation platform of elevator group scheduling.

针对电梯群控调度过程中交通流的不确定性和优化求解复杂性问题，本文通过建立电梯群控调度系统的鲁棒离散优化模型，实现了一种基于鲁棒离散优化理论的新的电梯群控优化调度算法。

According to fully implicit method, seepage model of low-permeability fractured gas reservoirs are discretized with finite difference method, and corresponding numerical model, coefficient matrix and matrix element are obtained; then based on modern software engineering, numerical simulation software was correspondingly developed with Fortran95 programming language

按照全隐式离散化方法，采用有限差分方法对低渗裂缝性气藏渗流数学模型进行了离散，得到了相应的数值模型、系数矩阵和矩阵元素。然后基于现代软件工程的基本思想，用Fortran95语言开发了相应的数值模拟软件

Recent years as development of the computer and software, it becomes reality using numeric simulation to research grouting in clay. Using the software of PFC2D, the grouting in clay is lucubrated and such achievements are reached: Grouting technologies in existence grouting material and serosity are studied and rational methods are put forward in choosing grouting technology and serosity.(2) Base on numeric simulation biax test a method is explored to simulate clay with PFC2D.(3) A method is explored to simulate grouting using PFC2D.(4) The relation between serosity pressure and diffuseness of grouting in clay with different initial stress is studied.(5) The stress transformation of clay is studied during grouting.(6) The stress distribution is studied under different serosity pressure.(7) The normal stresss and shear stresss at any section are studied.

近年来随着计算技术的发展，使得采用数值模拟的方式研究均质土体中的注浆成为可能，本文则利用离散元程序PFC2D对均质土体中注浆进行了研究，主要做了以下几方面的工作：(1)研究了现有注浆加固技术、注浆材料以及浆液的性质，阐述了合理选择注浆方式以及浆液的方法；(2)采用数值双轴实验，探索了应用离散元模型模拟土体的方法：(3)探索了采用颗粒流程序进行注浆数值模拟的方法途径；(4)研究了在粘土中注浆不同侧向土压力条件下浆液扩散范围与注浆压力规律；(5)研究了注浆过程中不同阶段土体中压应力的变化；(6)研究了不同注浆压力对土体应力分稚的影响：(7)研究了注浆过程中土体中任一截面处正应力与剪应力的对比关系。

In the following chapters, a set of three-dimensional mathematical models involving the heat transfer of the coolant turbulent flow and heat conduction coupling, which is applicable in engineering, was established according to currency N-S control equation, the SIMPLER algorithm in an unstaggered grid system, SMART scheme and k- e turbulence model are used in the flowfield ; The method of whole-field dispersed and solved are appled in the temperature field.

流场计算中，采用同位网格上的SIMPLER算法和低雷诺数κ-ε湍流模型，对流扩散项采用SMART格式离散；温度场计算中采用整场离散，整场求解。

The method of finite element discrete and optimal parameter back analysis is adopted.(3) Concentrated on the question of high external water pressure of the deep-lying tunnel, the basic theory and method calculating external water pressure are systematically studied.(4) Based on Jinping cascade 2 hydropower station, numerical simulation rain infiltration of seepage field under different drainage pattern and grouting pattern are studied, also, the high external water pressure is analyzed and studied and some seepage control measures are put forward.

2采用有限元离散—优化法进行参数的反演分析；(3)针对深埋隧洞的高外水压力问题，进一步分析和研究了衬砌水荷载及外水压力的作用机理和计算方法；(4)以锦屏二级水电站深埋长引水隧洞作为本文的主要研究对象，采用考虑降雨入渗渗流场分析的方法对排水方案和灌浆封堵方案不同情况下的渗流场的水头分布进行了数值模拟，并对其外水压力进行了分析和研究，提出了渗流控制的具体措施。

Two test pieces with satin surface and rib surface were designed under conditions of different distribution of heat flow density and different air flux.

流场计算中，采用同位网格上的SIMPLER算法和低雷诺数κ-ε湍流模型，对流扩散项采用SMART格式离散；温度场计算中采用整场离散，整场求解。

After the axial profile curves of back shroud are determined, the iterative formulae for calculating the curves of front shroud of impeller are derived in such a way that the flow passage area of the impeller profile varies with the middle curve of passage L linearly.

在确定叶轮后盖板的轴面流道曲线后，从过流断面积F沿流道中线L线性变化出发，推导出前盖板曲线的离散迭代公式。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。