数值技术

Obviously the thermal conditions of dies and die castings and the fluid flow of liquid metal have critical influence on the quality of casting product, the production rate and the die life. Hence, computer numerical simulation has become an efficient tool to analyze as well as to control the thermal and fluid flow fields in die casting process.

压铸过程的温度场和流场是影响压铸产品质量、生产率和模具寿命的重要因素，计算机数值模拟技术为压铸温度场和流场的研究提供了有效的手段，同时也为压铸工作者控制压铸温度场和流场提供了有力的工具。

Simultaneously, the exports of ionization rate and nonionzed concentration are set up as a powerful tool for studying thoroughly the freeze-out effect. dN〓/dp and dN〓/dn are neglected in the linearized equation system of the iteration methods of Newton and Gummel, due to having lower 15 orders or more than dN〓/dn and dN〓/dp, thus the computing effort is cut down with no effect on precision. A new cut-off technique is adopted to accelerate the convergence speed, about twice reduced for Newton iteration method and six times or so for Gummel iteration method. The approximate formulae of Fermi-Dirac statistics are also put forward with simpler form and higher precision. 3. A term dependent on time is added to the electron and hole current succession equations respectively. It is only this model that conservation of charge in transient analysis and alternating small-signal analysis at low temperature can be kept by. 4. The performance of SE-PISCES is explained by the simulation example of PISCES-2B, diode.

研究了低温半导体器件模拟的数值方法：对载流子浓度进行了新的归一化；编制了不考虑掺杂所引进的内建电场时的电离率计算程序；由于低温杂质电离率随偏压状态而变化，为此编制了每次求解迭代时的电离浓度计算程序，并将其插入到求解迭代程序中；同时，设置了杂质电离率和未电离杂质浓度的出口点，为更深入地研究冻析效应提供了有力工具；在Newton迭代法和Gummel迭代法的线性化方程组中忽略了dN〓/dp、dN〓/dn，是因为它们比dN〓/dn、dN〓/dp低15个数量级以上，这样减小了计算量又不影响模拟精度；对Newton迭代法和Gummel迭代法采取了新的截断技术，提高了收敛速度，Newton法迭代法和两次左右，Gummel法减少六次左右；给出了表达式更简单而精度更高的Fermi-Dirac积分近似计算公式。

Most studies on freezing process of porous media are concentrated on numerical simulation taking advantage of computer technology.

多数对多孔介质冻结过程的研究是建立模型借助于计算机技术给定数值解。

Based on it,three dimensional numerical simulation of Natural Gas Rebuming is carried out.With the typical tangentially fired boilers in China as research object,it is set up that the pulverized coal combustion models and the NOx models.Through CFD method,the combustion process is simulated.All of these will promote the engineering applications of fuel reburning technology.

在此基础上，对燃煤锅炉的天然气再燃过程进行了系统的三维数值模拟，以我国典型的四角切圆煤粉锅炉为研究对象，建立了煤粉扩散燃烧和污染物NOx生成-还原模型，采用计算流体力学方法，模拟其燃烧过程，促进了再燃低NOx技术应用的推广。

Numerical simulation of temperature field in high temperature regenerative heating furnace was studied by using Fluent software.

对天然气在高温蓄热式加热炉中的燃烧技术，运用 Fluent 软件通过数值模拟进行了研究。

Here the most recent research results of numerical simulation and controlling on blast furnace lining corrosion were reviewed since 1960s, and some important problems of present were discussed, and some proposes for future development trends were given, which will be helpful for the future theory and experiment research.

本文综述了从20世纪60年代以来有关高炉炉衬侵蚀的数值模拟和控制技术的国内外最新研究成果，并对目前存在的一些主要问题进行了分析讨论，对今后研究的发展趋势提出了建议，希望能有助于今后开展相关的理论和实验研究。

According to the real dynamic geologic feature of the volcanic gas reservoirs in Shengping developing zone of Xushen Gas Filed, the authors applied integrally the methods of gas reservoir engineering, gas-producing engineering, economic evaluation and gas reservoir numerical simulation to analyze and prove synthetically the economic boundaries such as entrained liquid threshold, single well location outcome boundary, economic ultimate distances between wells, rational gas- producing rate and so on for gas reservoir development technologies.

依据升平开发区火山岩气藏实际地质动态特征，综合应用气藏工程、采气工程、经济评价和气藏数值模拟等方法，对气井临界携液产量、单井布井产量界限、布井经济极限井距和气藏合理采气速度等气藏开发技术经济界限进行了系统的分析和论证。

The discussion on the gauge problem which is the point at issue in 3D eddy current computation suggests that the FE solution from 〓, V-ψ formulation without gauge is unique.

本文以RFEC缺损响应和检测机理的电磁场数值分析方法为研究对象，在数学模型、算法和计算技术上进行了研究和探讨。

By a simulation with numerical computing to the grab bucket failure from heavy deformation under load, this paper gives an advice to improve the grab according to the analvzed result.

对抓斗受力后发生严重变形而失效的工况进行数值模拟仿真计算，根据分析结果提出改进措施，并在同样的工况下对修复方案进行仿真分析，为抓斗的修复工作提供技术支持。

Although the reinforcement technology has been applied widely in highway construction, there are many challenges in the field which puzzle highway engineer for a long time in China. Mechanical behavior and design method of reinforced subgrades in highways have been studied thoroughly based on

针对加筋土路基的关键问题，通过现场调查、理论分析、室内试验、数值模拟和现场测试，对加筋土路基的主要工程问题、静力荷载和行车荷载作用下加筋土路基的力学行为、加筋土路基的设计计算理论、方法和参数以及加筋土路基施工技术进行了深入系统的研究。

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。