查询词典 numerical system

The way of Arnoldi is based upon the principle of Galerkin, which is closed to the solution of the linear numerical system. Here, we call the solution as Generalized Minimum Residual.

基于Galerkin原理的Arnoldi算法是求解这种线性代数方程组的近似算法，以下称这种方法为广义极小残余算法。

Exact numerical system modal is needed to control structure vibration.

结构振动控制模型结构振动控制需要精确的系统数学模型，同时控制的实时性要求系统的模型阶数不能过高。

The numerical system of equation is solved using an implicit line relaxation scheme.

离散后的数值系统使用隐式线松弛方法迭代求解。

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。

This paper mainly illtroduces the structure function of every pari and elementof CNC system.

本文主要介绍了计算机数控（CNC，Computer Numerical Control）系统的结构、各部分的功能和工作原理。

One of the important tasks in Resin Transfer Molding is the selection of appropriate processing parameters, so that the mold cavity will be filled completely and the composite quality can be guaranteed. Successful completion of these tasks requires knowledge of the resin flow, especially the resin flow front profiles, the pressure distribution, temperature distribution and the resin conversion distribution et al. In this paper, the governing equations of resin flow are presented on the base of the seepage mechanics, the thermodynamics and the chemical kinetics. The unlumped temperature system i.

中文题名树脂传递模塑工艺过程数值模拟与固化过程监测研究副题名外文题名 Investigation on numerical simulation and curing process monitoring of resin transfer molding 论文作者李海晨导师王彪教授学科专业工程力学研究领域\研究方向学位级别博士学位授予单位哈尔滨工业大学学位授予日期2002 论文页码总数10，121页关键词树脂固化光栅树脂传递模塑复合材料馆藏号BSLW /2003 /TQ320 /7 树脂传递模塑(Resin Transfer Molding，RTM)工艺过程研究的主要任务之一是选择合适的工艺参数，以使树脂充分润湿增强纤维，保证固化后产品质量。

Mastercam9.0 numerical control system first makes the NCI files according to graph and processing information. But NCI files can not transmit directly to numerical control machine tool, it cant control numerical control machine tool normally by special post processing programme of all kinds of numerical control system until it transforms NCI files to NC files received and identified by numerical control system.

采用MasterCAM9.0进行数控加工时，首先根据图形信息和加工信息生成NCI文件，但NCI文件不能直接传送给数控机床，还必须通过各数控系统专用的后置处理程序，将NCI文件转换成数控系统可以接受和识别的NC文件，才能控制数控机床正常工作。

In the left tool carriage ,the ball leadscrew,the servo motor and single gear reducer were displaced,and the coordinated movement about X and Z axis could been implemented by semi-closed loop control of SINUERRIK 802D numerical system.

介绍了在保留右刀架机械结构和操作功能不变的基础上对C5225立式车床的进给系统进行数控化改造。

In the left tool carriage, the ball leadscrew、the servo motor and single gear reducer were displaced,and the coordinated movement about X and Z axis could be implemented by semi-closed loop control of SINUERRIK 802D numerical system.

左刀架采用滚珠丝杠、伺服电机和一级齿轮减速，并利用SINUMERIK 802D数控系统的半闭环控制实现左刀架的X轴和Z轴联动控制，机床改造后，大大扩大了机床的加工范围，同时提高了生产效率和加工精度。

At present, electric propulsion technology has been widely applied in space flight missions and ascendant performance of electric thrusters makes them a substitution of traditional chemical propulsion system like monopropellant and bipropellant motors gradually.

中文题名电弧喷射推力器数值模拟与实验研究副题名外文题名 Numerical simulation and experimental study on arcjet thrusters 论文作者汤海滨导师刘宇教授学科专业航空宇航推进理论与工程研究领域\研究方向学位级别博士学位授予单位北京航空航天大学学位授予日期2002 论文页码总数134页关键词电弧喷射推力器火箭发动机电推进推力器馆藏号BSLW /2002 /V439 /3 目前，电推进装置已广泛地用于空间飞行任务，优越的性能使其正在逐步取代单、双组元等传统的化学推进系统。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。