数值方法

Using numerical simulation technology and method of orthogonal experiment design and single factor rotating optimization, this thesis makes a study of "lost core injection ", thus achieve the optimization of the parameters of molding process, to offer basic reference when developing production technology and mould of the plastics intake manifold. Based on the study of the status in quo and development trend of weight reduction on automobile, the application of plastics to automobile and intake manifold, then under the guidance of theory model and numerical simulation technology in the process of high polymer material, this thesis launches flowing main research work: First of all, on the basis of the three-dimensional model of the part and finite element net model, several designs of gating and running system are numerically simulated and analyzed via MPA of Moldflow.

本文在对当今汽车轻量化、零部件塑料化以及的汽车进气歧管塑料化的发展现状和发展趋势进行了研究和简要介绍，然后在高分子材料成型过程中的理论模型和数值计算方法的指导下，展开主要的研究工作：首先，在零件三维模型和有限元网格模型的基础上，使用Moldflow 的MPA模块对塑料进气歧管的多个浇注系统设计方案进行数值模拟，通过分析各个方案的充填质量、熔接线位置及数量等指标，得到了综合质量较高的4 个进料口的浇口位置及半限制型浇口大小的浇注系统。

To solve the difficulties of the discretization and application of fractional order controllers, evaluation strategies of digital realization of FOC are investigated. The realization principle and process of various discretization methods are discussed.

针对分数阶控制器数值计算和应用难的问题，提出了分数阶微积分算子数字实现方法的评估策略，分析了分数阶微积分算子的多种数值计算法的机理和实现步骤。

The diffraction distributions of Gaussian beam limited by the circular apertures with different sizes in scanning objectives focal plane were studied, and then the effective spot radius in focal plane was calculated using second moment and compared with the ideal one. The influence of apertures with different sizes on resolution was analyzed.

在不同孔径圆孔的限制下，对扫描物镜焦面上的衍射光场分布进行数值计算，并利用二阶矩统计的方法对焦面上的等效光斑半径进行数值计算，将其与不受限时的理想情况进行对比，分析孔径尺度对激光束扫描系统分辨率的影响。

Three-dimension turbulent flow in forebay of pumping station is numerically simulated with finite volume method and hybrid grid technique.

文摘：应用水平方向上是正交贴体坐标系、垂直方向上是笛卡尔坐标系的混合数值网络系统和三维紊流数值模拟的方法，模拟了泵站前池水流流态。

Based on rubbing model of a two-disk rotor-stator system with consideration of both rotor and stator dynamics,a numerical integration program is applied to numerical simulation and analysis of the nonlinear dynamics of this system,such as bifurcation,Poincare section map,trajectory of axes,phase trajectory,frequency spectrum diagram and time response.

基于一新型径向-轴向复合碰摩双盘转子-机匣力学模型，利用数值积分和Poincare映射方法，对转子-机匣系统由于径向-轴向碰摩故障导致的非线性动力学行为进行了数值仿真研究，给出了系统响应随转速和偏心量变化的分岔图和一些典型的Poincare截面图、相轨图、轴心轨迹、幅值谱图和时域响应等。

In this paper, we have been solved Fresnel integral equations by the numerical iterative method in virtual confocal unstable cavity with the strip mirrors of cylindrical surfaces.

用数值迭代方法求解了柱面条状虚共焦非稳腔的积分方程组。对相同及不同的菲涅耳数NF和不同的放大率m等情况进行了数值计算。

The evolution of frontal rainbands happening during the frontogenesis induced by deformation field is investigated through the numerical cloud model. Besides, in order to get insight from the results of numerical simulations, the semigeostrophic frontogenesis model is used to investigate the effect of diabatic heating on the frontogenesis and the analytical method of WKBJ is used to study the influence of large-scale deformation field and frontal circulation on the development of symmetric disturbance happened in the frontal zone.

为了加深对数值模拟结果的理解，还利用半地转模式对非绝热加热影响锋生的过程进行了讨论，通过WKBJ方法讨论了变形场锋生条件下对称扰动的发展，从中可以了解大尺度变形场和锋生环流对中尺度扰动的作用，这方面的工作可以对前面非静力数值模拟结果的理解提供帮助。

Therefore, a new and functional numerical method and quantitative analysis method are provided.

因此对该类问题的研究提供了新的实用的数值解法和数值分析方法。

Methods In the first place,the mathematical model of the dynamical response of viscoelastic thin plates is established in physical space,then the fundamental equation in Laplace domain is obtained by using Laplace transformation.

首先在物理空间建立了粘弹性薄板动力响应问题的数学模型，然后利用拉普拉斯变换得到拉氏变换域的基本方程；利用基本方程的基本解，由边界元方法得到边界积分方程，并求得数值解；最后通过数值 Laplace 逆变换得到原问题的解。

Concretely, firstly with Timoshenko beams, the fundamental formulae of solutions of dynamical equations, boundary conditions and initial conditions have been transformed by Laplace transformation. Secondly, in the Laplace regions , we gain the analytical solutions of impact forces at the impact contact points, shear and maximum inverse stress of beams. Then, by using Durbin numerical inverse method, we gain the numerical solutions of Timoshenko beams under various restriction conditions. Moreover, the graphs about impact forces at the impact contact points, shear and maximum inverse stress of beams can be obtained too.

把Timoshenko梁力学模型动力学方程的基本解形式、边界条件以及初始条件进行Laplace变换，在Laplace区域得到了冲击接触处的冲击力、整个梁的最大弯曲应力和剪力的解析解，然后利用Durbin数值反演的方法得到了各种约束条件下的Timoshenko梁模型时间-空间的数值解，得到了冲击接触处的冲击力、梁各处的最大弯曲应力和剪力的曲线图。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。