查询词典 numerical algorithm

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。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory. The key techniques used in numerical simulation of the three-dimensional extrusion from dies such as decision of boundary conditions, creation of initial velocity field, selection of penalty factor, high Weissenberg number problem , regeneration of the free surface were studied in detail.

中文题名聚合物异型材口模挤出三维流动研究副题名外文题名 Study on three-dimensional flow of polymer melts during the process of profile extrusion from dies 论文作者涂志刚导师柳和生包忠诩教授学科专业材料加工工程研究领域\研究方向学位级别博士学位授予单位南昌大学学位授予日期2001 论文页码总数148页关键词挤出成型聚合物材料挤出口模聚合物异型材馆藏号BSLW /2003 /TQ320 /9 本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

A comprehensive review and expectation about researching status in quo and development trends of viscous flow numerical simulation technique are given in this paper and grids generation methods, numerical computation methods, turbulent model and moving boundary simulation methods are the emphasis study in the paper. On the basic of above job a mathematical model of simulation turbulent flow with free surface is established and triumphantly applied to numerical computation on 2D spillway and 3D spillway with frusta of brake.

本文针对粘流场数值模拟技术的研究现状和发展动态作了比较全面的回顾与展望，重点研究了网格生成技术、数值求解技术、湍流模型技术和动边界模拟技术，在此基础上建立了模拟自由面湍流场的数学模型，并成功地应用到二维溢流坝和带闸墩的三维溢流坝过坝水流的数值计算。

The development trend of the numerical control knife rest is: With the development of numerical control lathe, numerical control knife rest begin to change one hundred sheets , electric liquid is it urge and urge direction develop while being servo to make up fast.

数控刀架的发展趋势是：随着数控车床的发展，数控刀架开始向快速换刀、电液组合驱动和伺服驱动方向发展。

The article definitions the severals and numerical resources industries to turn the related concept first, introduce the present condition of the local and numerical resources construction, and carried on the introduction and simple analysis to the development of the local and numerical resources business enterprise.

文章首先界定了几个与数字资源产业化相关的概念，介绍了国内数字资源建设的现状，并对国内数字资源企业的发展进行了介绍和简单的分析。接下来对国内数字资源企业的产生背景做了全面的分析，并对它们的发展现状做了比较。然后对目前国内数字资源产业的发展环境做了分析。

The company has the advanced plate work processing equipment, the static electricity spraying equipment 2 sets, including high accuracy numerical control punch press, numerical control knee bend machine, numerical control plate cutter, static electricity spraying equipment, other each kind of equipment.

公司拥有先进的钣金加工设备，静电喷涂设备2套，包括高精度数控冲床，数控折弯机，数控剪板机，静电喷涂设备，其他各种设备。

During the four years study on the project, we develop a dynamical forecast model that describing the subtropical ridge surface. A new theory on the role of the land-sea thermal difference on the formation of the Subtropical High is advanced. It is concluded that in the summer subtropics over each continent and its adjacent ocean LO, SE, CO, and a double-dominant heating from west to east compose a LOSECOD heating quadruplet. The influence of the Eurasia continent on SH varies according to the seasonal variation. From the ideal numerical simulation it is shown the important role of the Eaiuan continent and the huge topography on the mechanism of formation and mantanence of the SH during the summer. It is verified by the numerical simulation that the extension of the subtropical continent into the tropics greatly enhances the " East Asian monsoon". Through the Rossby energy dissipation theory it is verified that the deep latent convective heating induces the onset of the South China Sea monsoon over the Bay of Bengal. The relationship and mechanism between the precipitaiton over the East Asia and the Subtropicla high is illustrated by the data. It is also found the close phase lock between the east-west shift of the SH and the disturbence of the east wind belt over the tropical troposphere. The interaction between the structure and activity feature of the SH and the Meiyu over the Yangtze-Huaihe river valley is revealed from the data. The numerical simulation verified the impact of the different SH pattern on the path of the typhoon.

本项目的研究发展了描述副热带高压脊面变化的动力模型，提出了夏季副热带地区四叶型非绝热加热分布型及相应环流拼图的创新理论；明确了大陆尺度的海陆热力差异在副热带高压形成中的作用；指出欧亚地形对副热带高压和气候的影响随季节变化而变化，通过数值试验证明春季青藏高原的感热加热对亚洲夏季风的爆发地点起了&锚定&的作用，进一步证实了副热带高压断裂和亚洲夏季风的最早爆发地点发生在孟加拉湾东岸；利用Rossby波能量频散理论证明了孟加拉湾深对流潜热释放诱导南海季风爆发的机制；揭示了东亚季风降水的季节内变化与西太副高的关系及机理；揭示了西太副高与东西风带中扰动之间的相互作用过程，指出西太副高的东西活动与热带对流层上空东风带扰动和中纬度西风带扰动的移动和锁相密切相关；研究了夏季淮河流域梅雨期间副高结构和活动特征及其与江淮暴雨的相互作用；验证了不同副热带高压形态对台风路径的不同影响；通过数值试验证明了欧亚大陆和青藏高原等大地形对副热带高压形成和维持的重要作用。

It is available to carry out numerical simulation and fluid dynamic analysis further. Based on Frozen-Rotor Approach and Rotor-Stator Approach, the numerical simulation was carried out in the centrifugal pump and the numerical results showed that the flow in the impeller and volute of centrifugal pump is periodically unsteady. Due to the interaction between impeller and volute the flow is characterized by pressure fluctuations and it is the strongest at impeller outlet and at the vicinity of the tongue. The unsteady pressure fluctuations are also one of the most important reasons to induce vibration and noise. Secondly, the flow field of the volute is characteristic of the vortex flow, and the vortex flow presents very complicated developing process which is creating, increasing and dissipating every now and then. All these lead to very large flow loss in the volute.

采用Frozen-Rotor冻结转子模式和Rotor-Stator滑移界面模式系统开展了不同工况下离心泵内叶轮与蜗壳耦合的定常和非定常流动研究，结果表明由于叶轮与蜗壳的干扰蜗壳进口周向流动的不均匀性是非常强烈的，特别是叶轮与蜗舌间的相互干扰最为强烈，一直影响到叶轮进口和蜗壳扩散管出口的流场；在蜗壳内整个流动是以旋涡形式向出口推进的，并随着包角的变化旋涡表现出十分复杂的产生、发展和耗散的演化过程，导致蜗壳内较大的流动损失。

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。

The numerical simulation of the detection signal was implemented with the theory of diffraction optics, and the numerical simulation of the wavefront reconstruction was realized with Green function algorithm under Neumann boundary conditions.

根据衍射光学理论，对其探测信号进行数值模拟，并利用Neumann边界条件的Green函数法对其波前重构进行数值模拟。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。