查询词典 numerical computation

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。

Incurrent research, aiming at the rupture problem engendered in the shooting process of acertain 5.56mm automatic rifle, the strain and stress distributions on the cartridge caseunder the action of axial pull have been analyzed. Based on the theories of elastic-plasticmechanics and contact mechanics, a mathematic and physical model of the cartridge-caseand chamber system has been set up; and based on the platform of the general softwarepackage APDL of ANSYS for finite element analysis, a parameterized model of thecartridge-case and chamber system has also been established. The method for nonlinearFEA has been adopted to analyze the stress distribution on the entire cartridge-case andchamber system, and the method of contact element has been employed to investigate thecontact stress between the cartridge case and chamber, and then the influences of frictioncoefficient and locking space on the static and dynamic stress and strain response of thecartridge case and chamber to the action of power gas have also been discussed. On thebasis of a lot of numerical tests, a kind of element Plane13, which is concentrated incoupled computation of heat and construction, has been used finally to simulate thetransient response of the cartridge-case and chamber system to the power gas. Throughloading the temporary thermal characteristics of explosive gas in the procedure of emulate, the corresponding transient thermal stress distributed on the entire system under thecombined load of transient thermal stress and transient pressure has been obtained. Owingto these comprehensive considerations, the numerical results obtained in this paperrepresent the actual situations comparatively exactly.

本文针对某5.56mm自动步枪在工作中出现断壳的问题，分析了弹壳在轴向拉力作用下的应力应变；基于弹塑性力学及接触理论，建立了弹壳弹膛系统的数学、物理学模型，在通用有限元ANSYS软件的参数化建模工具APDL平台上，建立了弹壳弹膛系统的参数化模型；采用非线性有限元法计算了弹壳弹膛系统的整体应力，引入接触单元法分析弹壳和弹膛的接触压力，探讨了在不同的摩擦系数和不同的闭锁间隙对弹壳弹膛静、动态响应的影响；本文进行了大量的尝试，最后确定采用热、结构耦合单元Plane13，在计算中加载了火药气体的温度历程，成功的获得了弹壳弹膛系统在瞬态的热载荷和瞬态的压力载荷同时作用下弹壳弹膛系统的热应力数值解，考虑因素全面，比较真实的反映了弹壳弹膛系统在火药气体压力和热载荷下作用的情况。

The key elements and techniques of the numerical wind tunnel are studied and analyzed.The basic idea of CFD is expatiated and the whole working process is presented.Discrete methods of the control equations based on the finite volume method and the PISO algorithm about the fluid numerical computation are researched also.

对基于CFD的数值风洞关键基础和技术进行研究分析，阐述了CFD的基本思想，研究了基于有限体积法的控制方程的离散方法以及流场的数值求解的PISO算法。

The velocity-stress pseudospectral method, an efficiently numerical modeling method, is easy to implement, with a high computation efficiency and can overcome numerical diffusion of the frequency efficiently.

模拟结果表明，伪谱法是一种有效的地震波数值模拟方法：易于实现，计算速度快、计算效率高，其计算速度是有限差分方法的数倍，能有效克服数值频散。

In order to improve the efficiency, an implementing scheme (according to the distribution of strain energy density) was suggested when to consider the fact that the high gradient usually appears only in a very local region, especially in the case of huge amount of computation. All programming has been finished on the platform of commercial codes Mathmatica and Fortran.4. A number of numerical examples and applications were presented to verify the proposed Bezier-Based Element Method. The engineering cases include: the belt die for diamond synthesize, the main frame of wire-rounded press, the hydraulic cylinder of open die forging press. The numerical results show that the BBEM has some good performances.

通过大量的数值算例来考证所构建的各种类型单元，并应用于人造金刚石年轮模具、钢丝缠绕预应力机架和液压机工作缸等实际问题的结构分析；结果表明：所构建的Bezier耦合单元具有描述较大梯度变化场(如位移场、应力应变场等)的能力，该方法不改变单元的大小和形状，保持单元的自由度数不变，而通过调节中间可动节点的位置改变单元内部的场分布，只需少量单元即可较精确地模拟较大的梯度变化；可为有效求解高梯度问题提供新思路，对实际工程应用具有重要意义。

The tracer migration that the tracer concentration continuously injecting into semi-infinite sand column(initialization velocity is zero) and the pollutant continuously enter into aquifer through a discharging well that completely enter into the dive aquifer are two representative groundwater pollution problems ,Then this paper respectively sets above two decided solution problems and the union simulation problem of groundwater and solute as examples, from the question description, the mathematical model selection and determination, the parameters selecting to carry on the value computation, the read-write of attribute data , visualizes by the IDL programs, carries on the numerical simulation and the visualization post-processing to the above groundwater pollution problems, and according to the numerical solution and the solute migration curves, briefly analyzes and predicts the temporal and spatial distribution features and distribution range of contaminant concentration.

然后分别以半无限长沙柱中连续注入示踪剂浓度的运移、污染物通过一完全进入潜水层的排放井连续进入含水层这两个典型地下水污染定解问题及地下水流和水质联合模拟问题为例，从问题描述、数学模型选取确定、参数选取到运用IDL编程进行数值计算、属性数据读写、可视化，对上述地下水污染问题进行数值模拟和可视化的后处理，并根据数值模拟的数值结果和溶质运移曲线，对污染物浓度的分布范围及随时空变化趋势作了简要分析预测。

As important ways for numerical solutions of partial differential equations, spectral methods have been developed rapidly in the past several decades. They not only have been widely applied to numerical simulations in various fields such as physics, mechanics, aerology, oceanics etc, and their theories of numerical analysis also tend to perfect.

作为数值求解的一种手段，谱方法在近几十年得到了蓬勃的发展，它不仅被广泛运用于物理、力学、大气、海洋等领域的数值计算，而且它的数值分析理论也不断地趋于完善。

The company produces the processing equipment to be advanced, check-out facility excellent, has the numerical control lathe, the numerical control drilling machine, the machining center, the numerical control gear-hobbing machine, the gear shaper, the fine borer, the universal milling machines, each kind of grinder, the table planer, the booklet bender, the large-scale lathe, the mechanical slicer, high intermediate frequency quenching, the well type, the box-type hardening furnace, the tempering furnace, the automatic welding machine, the X-ray crack detection machine, the cloth, the Rockwell tester; Electric hoist test platform, sound-level meter, varnish film thickness gauge, altazimuth, level; The material analysis laboratory, the metallography analysis room and so on full had guaranteed strictly the vehicle, the mill, dig, rub, pull, the boring, to drill, the ramming, cutting, the angle iron, the chemical examination and the heat treatment and so on complete technical process.

公司生产加工设备先进，检测设备精良，拥有数控车床、数控钻床、加工中心、数控滚齿机、插齿机、精密镗床、万能铣床、各种磨床、龙门刨床、折弯机、大型车床、刨床、高中频淬火、井式、箱式淬火炉、回火炉、自动焊机、 X射线探伤机、布、洛氏硬度计；电动葫芦试验台、声级计、漆膜测厚仪、经纬仪、水准仪；材料分析化验室，金相分析室等充分严格保证了车、铣、刨、磨、拉、镗、钻、冲压、切割、弯板、化验及热处理等全部工艺流程。

The unique advantage of this halfanalytical numerical method is that the analytical process of Conformal Mapping can transform an irregular area into a regular one such as a rectangle. Therefore, the discretization error of numerical methods on the boundary can be avoided, and the numerical algorithm can be implemented more easily, with the computing efficiency improved.

这种保角变换的半解析数值方法的突出优点是：利用前期的保角变换解析处理将不规则的场域转化为规则的矩形域，从而避免了纯数值技术对复杂边界的离散化误差，降低了后期数值计算的算法复杂度，并提高了计算效率。

Considering complicated conditions of the coastal dynamic environment, sediment dynamics, and together with the immature sediment itself, the predicted results will be somewhat limited if only with numerical model. So, in order to obtain microcosmic quantitative assessment and macroscopically understanding, numerical model is combined with field observations in the thesis. Firstly, the tidal current, SSC distribution, benthal deposited materials were basically analyzed by field observations. Then, the tidal current, SSC distribution, and the erosion and accumulation of the seabed were simulated with the numerical model of ECOMSED.

但由于海岸动力环境多变，泥沙运动复杂，加之泥沙问题本身的复杂性，如仅用数学模型，其预测结果将受到一定的限制，故本文采用实测调查与数学模型计算相结合的方法，宏观把握，微观量化，在掌握岚山港西突堤工程所在海域潮流、悬沙量分布、表层底质沉积物类型及特点基本态势的基础上，紧扣开发工程可能引起潮流场变化，分析工程后悬沙量、海底冲淤变化及其空间分布，进而建立潮流作用下的泥沙输运数学模型，首先比较好地模拟目前岚山港西突堤工程附近海域的潮流场和悬沙场，然后预测海湾沿岸可能引起的冲淤强度变化和冲淤区域的空间分布。

That snake Alaric named Archbishop...

庇护。。。那个毒如蛇蝎的Alaric被命名为大教主。。。

You have done lots of magical things to be amazed at.

你做了很多神奇的事物感到惊讶。