Simulation Method of Dynamic Characteristics of Turbine Flow Sensor

Computational Fluid Dynamics (CFD) simulation is one of the important methods to study the performance and in-fluencing factors of turbine flow sensors. According to the working characteristics of the turbine flow sensor, the passive simulation method based on the six degrees of freedom (6-DOF) model and dynamic mesh is proposed in this paper. The reliability of the simulation method is verified by steady-state experiments and unsteady-state experiments. The results show that the trend of meter factor with flow rate acquired from the simulation is close to the experimental results, and the deviation between the simulation result and the experiment result is low with a maximum deviation of 2.88%. In the unsteady simulation study, the impeller speed changes with the inlet velocity of the turbine flow sensor, which has a good follow-up. The passive simulation method can be used to predict the dynamic performance of the turbine flow sensor.     

面向对象的液压与气压回路工作原理仿真软件开发

详细介绍了用于液压与气压传动课程教学的“面向对象的液压与气压回路工作原理仿真软件”的开发，该软件采用VB6．0、AutoCAD及Microsoft Visio在Win2000操作系统上开发而成，采用了面向对象的建模技术，实现了液压与气压原理图的自动识别及工作原理仿真。     

铝合金熔体旋转喷吹除气净化过程模拟

采用计算机模拟方法对铝合金熔体旋转喷吹除气净化过程的温度场以及流场进行分析。结果表明,在转杆内部放置一个导气管,可以显著降低气体温度,从而可以有效地解决旋转喷头由于熔剂因高温变软而堵塞的问题;旋转速度和进气流量对铝合金熔体旋转喷吹除气净化效果具有重要影响,应该根据具体情况选择合适的工艺参数。熔池为方形结构时,气体主要从对角处出去,而远离对角处的体积分数却显著降低,甚至可能发生吸气。     

低压铸造三维温度场的冷却边界条件处理

低压铸造模具结构比较复杂，存在多处冷却系统对模具进行强制冷却。对低压铸造的多种类型的界面根据其换热的特点作了大致分类。针对每种情况，考虑了冷却介质和冷却管道的个性参数，建立了相应的计算模型，并编制计算程序对实际铸件进行了模拟计算。     

机床爬行的仿真研究及控制措施

通过理论分析和数字仿真说明机床爬行的机理和原因，并针对各种原因全面介绍了国内外相应的防止方法和具体措施。     

不同模数下圆柱直齿轮成形的数值模拟及分析

论述了在直齿轮分度圆直径为定值时，变形程度与模数的关系。通过对三种不同模数的齿轮在特定的条件下温挤压成形数值模拟，结果及分析表明，随着齿轮模数的增大，变形程度也增大，金属向齿顶及周围流动就相对较多，齿形就容易充满，但齿轮头部内凹与头的齿部凸肚现象就越厉害。     

阳极焙烧炉节能的途径

指出结构设计是阳极焙烧炉节能降耗的关键。有了合理的炉体结构,再配以自动控制系统,合理的焙烧周期等条件,就能降低能耗。本文从炉体结构设计、挥发份燃烧、固体蓄热回收、炉体漏风和控制方法等方面,介绍了降低阳极焙烧炉能耗的途径,以及一些有效的操作方法。     

Molecular Dynamics Simulation of Micro Mechanisms in Slip Deformation Theory of Crystals

Based on the discussion that there should be a micromechanism that causes a macroscopic slip of mono-crystal copper, molecular dynamics simulations with the analytical displacement feld around a crack tip have been carried out. The result of the simulation shows that macroscopic shear slip in an f.c.c. mono-crystal copper occurs as discrete time events. This is because cross-slips occur in many places in a material such that a macroscopic shear slip is blocked until some critical state of deformation. A macroscopic shear slip then occurs suddenly at the critical state in which the area of disordered atomic arrangement has stretched from one end of a crystal to the other end. The reason why macroscopic shear slips occur in the directions of the slip planes of a crystal is attributed to the fact that the areas of disordered atomic arrangement develop only along those directions.     

低压铸造凝固模拟中时间步长的实用算法

针对低压铸造凝固模拟计算过程中存在的收敛性问题，提出了一种能够处理复杂边界条件的简单算法，准确地给出了临界时间步长，避免了计算发散的现象，同时减少了计算的工作量。     

建立企业管理信息系统的思想、方法及其开发途径

本文以系统工程的思想和方法为指导,就企业如何建立管理信息系统,尤其是对认真做好各项前期准备工作等方面的问题,作了较全面、深入的论述。