查询词典 numerical calculation

But in the numerical calculation process, such as numerical differentiation, if we use these numerical methods inadequately, then it may be induced non necessary numerical error, including round off and truncation error.

因而常必须以值方法替代解析解，但是在值计算的过程中，很容引入额外的计算误差，包括舍位误差与截断误差。

In this thesis, I summarize the theoretical calculation method, applied scope and notice of siphonic drainage system, and point out the advantage of siphonic drainage system compared with gravitation drainage system. In the archetype experiment study of siphonic drainage tube, I adopt different tube diameter and different structural height to survey the drainage volume and press in different place. I observe various kinds of flow state, and get chief factors which influence hydraulic peculiarity of system as the tube diameter or structural height, and find out the relevance of factor to flux. I apply CFD Fluent software and adopt standard k-ε model and RNG k-ε model, then use finite volume method and second-order upwind scheme to discrete numerical model, while coupling numeration of velocity field and press is based on SIMPLE. In the numerical simulation of curved part of tube, siphonic drainage tube experiment system and multi-outlet siphonic drainage system, I make research on internal velocity and press of system in different project condition by changing the tube diameter of curved part, negative press value in tube export and improving the quantity of water gutter. This thesis first adopts a method of combining archetype experiment and numerical simulation to study the siphonic drainage system, test and verify the validity of experiment and numerical simulation, and makefurther study on system, it solves the problems of limited testing conditions, and has a logical results, it can provide a valid method for optimizing and designing the drainage tube-net system. The conclusion have referring value for study and design of siphonic drainage system.

本文首先对虹吸式排水系统理论计算方法、适用范围以及注意事项做出总结，并分析了虹吸式排水系统的优势；再对虹吸式排水管道进行原型试验研究，采用不同管径不同立管高度，对系统流量、管道压强进行量测，观察了各种工况下的流态，对其水力特性进行研究分析，找出影响水力特性的落差、管径主要因素以及与排水量的关系；进一步应用计算流体力学Fluent软件，采用标准κ-ε模型与RNGκ-ε模型，计算过程应用有限体积法和二阶迎风格式对数值模型进行离散，速度和压力的耦合采用SIMPLE算法，分别对系统弯管段、虹吸排水管道试验系统、多斗虹吸式排水系统进行数值模拟分析，通过改变管段弯头处半径、管段出口负压值、增加雨水斗数对不同工况下系统内部的速度和压力进行研究；本文首次采用结合原型试验与数值模拟相结合的方法，对虹吸式屋面雨水排水系统进行研究，试验与模拟相互验证，并进行拓展，很好地解决了虹吸式屋面雨水排水系统由于试验条件限制问题，结果正确合理，为排水管网系统设计和优化研究提供了有效的方法，对工程设计有较好的参考价值。

The results of our numerical simulation show that the numerical method applied in our paper is practical, the calculation results match the actual situation properly; the digital images from numerical simulation possess a positive significance in understanding and improving the heat flow distribution of the meat dry kiln. The proposed method provides a feasible approach to analyze and improve the flow field of meat dry kiln with numerical simulation.

数值计算的结果表明：本文所用的数值计算方法是可行的，基本符合实际情况；所得计算结果分析图像对了解干燥窑中流场的分布情况和如何改善干燥窑流场分布具有积极的参考意义，本文所提出的方法为采用数值计算方法分析改善干燥窑流场问题提供了一种可行的手段。

The results of numerical analysis show that the elastic modular and the poisson ratio have no effect on two-dimensional bearing capacity, but can affect the ultimate bearing capacity of three-dimensional foundations and control the convergence and precision of finite element calculation; the earth pressure coefficient controls the geostatic stress of foundation, sequentially affects the ultimate bearing capacity of foundations and the convergence of numerical calculation. When calculating the ultimate bearing capacity of undrained saturated foundation, the complete formulation exists shear locking, and reduce formulation exists hourglassing, so the hybrid formulation is suitable to imitate the geomaterial. When the soil obeys nonrelevent flow rule, the yielding function is different from potential function, and the elastic-plastic matrix of soil is asymmetric, so the unsymmetry numerical solver and appropriate finite element mesh is required.

研究结果表明，土体弹性模量和泊松比对二维基础极限承载力没有影响，但是影响着三维矩形基础的极限承载力，控制着ABAQUS数值算法的计算精度与收敛速度；地基土压力系数控制着地基土体中的地应力平衡，从而影响着二维条形基础和三维矩形基础的极限承载力和地基破坏包络面；对于不排水饱和软黏土地基，常规的完全积分单元会造成剪力自锁现象，而减缩积分单元则存在过于柔化的现象，故采用杂交单元来模拟较合适；当土体服从非关联流动法则时，屈服函数与塑性势函数之间存在差异，从而导致土体弹塑性矩阵呈现非对称性，在有限元计算中必须采用非对称数值解法，并且合理地划分单元才能对极限承载力进行准确求解。

For the particular structure of water-lubricated plastic alloy bearings,with cannelures and low elastic modulus of plastic alloy bushes,and for the complicated numerical calculation of elastohydrodynamic lubrication,the multilevel method was introduced into the EHL numerical calculation of water-lubricated plastic alloy bearings,and the numerical results were attained successfully.

由于水润滑塑料合金轴承的特殊性：带有纵向的沟槽和轴承衬弹性模量低，以及弹流润滑的计算比较复杂，将多重网格法引入到水润滑塑料合金轴承的弹流润滑计算之中，成功地实现了数值解，为其理论研究奠定了基础。

The 3-dimension solid model of the 8th turbine rotor blade of some type aero engine is constructed in software UG, and the numerical calculation region of stream field in ECM is set up in special flow field calculation software FLUENT based on the principle of hydrodynamics. The distribution of 6-dimension forces is got after numerical calculation, and the equation between 6-dimision forces and interelectrode gap is set up.

基于流体力学原理，用UG造型出某型航空发动机8级涡轮转子叶片，用流场计算软件FLUENT构造电解加工中叶片的流场计算区域，经数值计算得到六维力的分布，并从理论上建立六维力与间隙之间的关系方程式，为后续试验研究提供了参考依据。

According to the algorithmic characteristics of video coding, general video decoder can be classified by three classic tasks. First is the low-leveled task for simple control, which focuses on calculation. It is called dense-calculation task when the requirement for calculation is higher. Second is the data-dependence task for simple calculation but sophisticate control, which belongs to middle-level task. More sub-states exist inside the task and the transition of the sub-states depends on input data and lacks of rules. Third is the simple-system task, part of advanced tasks, with simple calculation but no rules, the complexity of which mainly lies in the control of multi-tasks to complete certain function coordinately.

根据视频的编解码算法特性，一般的视频解码器可以分为三种典型的任务：以运算为主，控制简单的低级任务，当运算要求很高的时候我们可以称之为运算密集型任务；运算简单，但是控制复杂，任务内部子状态繁多，而且跳转依赖于输入数据而无规律，这类任务我们可以称之为数据依赖型任务，属于中级任务；运算简单而无规则，复杂度主要集中在控制多个任务协同进行以完成某一特定功能的简单系统型任务，属于高级任务。

With understanding the numerical control milling machine in cam processing utilization, thus people can complete analysis of the discoidal cam numerical control mill technological capability , the programming and the analysis of grooved cam numerical control mill technological capability, the compilation of numerical control processing technological document.

了解数控铣床在凸轮加工中的运用从而完成盘形凸轮数控铣工艺性分析及程序编制和槽形凸轮数控铣工艺性分析及编写数控加工工艺文件。

The numerical study is carried out for a KVLCC2 tanker. Firstly, for the ship in oblique motion in deep water, determination of the computational domain, check of the grid dependence and selection of the turbulence model in numerical simulation are investigated. The effectivity of the numerical method is validated by comparing the numerical results with experimental data published in literature and the experimental results obtained by oblique towing test in the towing tank of Shanghai Jiao Tong University.

以KVLCC2大型油轮为研究对象，首先对船舶深水斜航运动粘性流计算中计算区域的确定、网格依赖性的检验以及湍流模型的选取等问题进行研究，通过将本文数值计算结果与他人的试验结果和在上海交通大学拖曳水池进行的船模斜拖试验结果相比较，验证了本文数值方法的有效性。

Every industrialized country lists the numerical control technology and numerical control equipment as country's critical materials besides in the world, not only come to develop self numerical control technology and their estate adopting an important measure, and the effectuation blockades and restricts policy in the respect of the numerical control key technology and equipment "high-grade , precise , and advanced" to our country

此外世界上各工业发达国家还将数控技术及数控装备列为国家的战略物资，不仅采取重大措施来发展自己的数控技术及其产业，而且在"高精尖"数控关键技术和装备方面对我国实行封锁和限制政策

Tom: You are right, he worked hard all the time.

你是对的。他一直都是努力工作。

Take shortcomings,failures,and mockings of others as commonplace and a drive to complete oneself,hold your own opinion over the evalution and disscution divested from others,afterwards sink into the state of eliminate mistakes if any or encourge oneself being not being influenced by the sayinngs of others or having no ideas to do.

把缺点、失败及别人的耻笑等看成是一种常事，当成完善自己的动力，对别人的评价和议论自己心中有主见，做到&有则改之，无则加勉&，不为人言所左右或无所适从。