查询词典 numerical method

To all project practicality, the introduction is given to the operational characteristics, the methods for calculation and the researching actuality of the tail tunnels with sloping ceiling underground hydropower stations the Three Gorges. This paper has discussed in detail the characteristic method being the same with the compressive flow and the Priessmann solution being the same with the free-surface-pressure flow. And how to deal with boundary conditions has been expatiated. Also hydraulic transient process of tremendous load fluctuation in the tail tunnels with sloping ceiling has been numerical simulated and the Fortran program for numerical simulation has been given. The paper gain the maximal press for tail end of the shell, the maximal rising rate of rotational speed of generating set, the maximal vacuum degree for inlet of the tail tunnels and so on under 11 kinds conditions of tremendous load fluctuation. These conditions include the design conditions, the check conditions and the superposition conditions. Finally, the computing results have been analyzed and summarized. The end chapter is the general comment of the whole-length content and the describing of the intending view of researching.

本文以三峡右岸地下电站尾水洞设计为背景，从工程实际出发，阐述了变顶高尾水洞的工作特性、使用范围及其研究现状；详细论述了适用有压流的特征线法、适用明满交替流的普里斯曼解法等数学模型；边界条件的给定和明满交替流的计算方法；用Fonran语言编制了数值计算程序，对三峡右岸地下电站变顶高尾水洞的大波动工况进行了数值模拟，分别得出了在设计工况、校核工况和叠加工况下蜗壳末端最大压力上升值、机组最大转速上升值和尾水管进口最大真空度等重要参数；对数值计算结果进行了详细分析并得出了有价值的结论；最后展望了今后水电站变顶高尾水洞的研究方向。

Made the numerical simulations and experimental verification to the flow characteristics of J90 supercharge compressor using numerical simulation method.

采用数值模拟方法，对 J90增压器压气机内的流动和特性进行了数值模拟和实验验证。

The method can solve numerical problems as well as symbolic problems in which the coefficients are symbolics other than numerical values.

本文提出的这一方法用来求解数值模型和符号模型（即已知系数是符号而不是具体数值）的符号形式表达的最优解和/或求解问题的全部最优解。

When s=2 and s=3, we give the numerical experiments and compare it with the numerical experiments of symplectic Runge-Kutta method.

当s=2和s=3时给出了数值模拟并与对应的龙格-库塔方法以及同阶的非辛方法比较。

Numerical simulation to three-dimensional turbulent flow in multistage axial compressor blade row is carried out, where high resolution third-order ENN scheme is adopted to catch the shockwave and simulate the turbulent flow correctly, and LU-SGS implicit method is chosen to improve computation rate. A nicety and high efficiency numerical simulating system is thus constructed.

对多级轴流压气机叶栅内三维紊流流场进行数值模拟，采用高精度高分辨率的三阶ENN格式以保证对激波的捕捉和对紊流特征的正确模拟，利用LU-SGS隐式解法提高了计算速度，从而构成了一种既准确又高效的多级跨声速轴流压气机紊流流动数值求解系统。

Beginning with wave equation, the paper has deduced the propagation of gauss pulses in single mode fiber and fiber grating transmission compensation. The characteristics of cascaded phase-shift gratings are discussed by numerical simulations of coupled-mode theory and T-matrix method. The experimental works and measurement results are shown in this paper. On the other hand, we have introduced the basic theory of EDFA and figured out the characteristics for EDFA at different conditions by numerical simulation. Some experimental results for EDFA are also presented here. In this article, you can find the influence on Optical Fiber Amplifier by Gain Tilt, especially, the negative effect on CSO in CATV transmission system.

论文首先从波动方程入手，对高斯脉冲在单模光纤中的传播演化及光纤光栅透射补偿进行了详细的研究；较系统地介绍了光纤光栅的耦合模理论，并将传输矩阵计算法用于计算级连相移光纤光栅的光学特性；重点介绍了作者在光纤光栅刻制及特性测量方面所做的一些实验研究工作；较系统介绍了EDFA的基本理论，计算出各种条件下EDFA的光学特性，并进行了一些实验研究；综合分析光纤放大器对光纤传输系统的影响，特别分析了光纤放大器增益不平坦对光纤CATV系统中CSO恶化的原因及其解决方法，并研究了光纤布拉格光栅在稳定980nm泵浦源输出功率和输出波长方面的应用；结合一个基于光纤光栅和光纤放大器的光纤用户接入网方案，对光纤用户接入网的若干问题进行了理论与初步的实验研究。

Triple integral expression of the radiation impedance of square piston is deduced and the numerical results of the radiation impedance are calculated with the method of Gaussian numerical integral.

利用高斯数值积分方法，推导了方形活塞辐射阻抗的三重积分表达式，计算了方形活塞声源的辐射阻抗。

Analyzing the process in the paper, the hydromechanics model of the hydromechanical deep drawing is built up, and the method on the numerical simulation of the hydromechanical deep drawing is put forward, which is an effective approach to the numerical simulation.

本文通过对筒形件充液拉深工艺的分析，建立了接近实际的充液拉深流体力学模型。结合有限元数值模拟技术，提出了充液拉深流体压力行为在数值模拟分析中的实现方法，为充液拉深有限元数值模拟提供有效途径。

By using this method, the memory space is reduced observably while guaranteeing the numerical simulation accuracy through numerical simulation.

仿真结果表明，该方法在保证数值模拟精度的条件下，大幅削减了空间需求。

Some unique techniques including topographics smoothing, overbank flowing, numerical filtering, auto-adjusting of roughness were adopted in this numerical simulation, and ADI method was improved in sweep by two-direction and two-step scanning.

数值模拟中还采用了地形平滑、水流漫滩、数值滤波及自动调糙率等几种处理技术，并对ADI法进行了双向双步扫描改进。

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。