PENALTY UPWIND FINITE ELEMENT METHOD FOR DIFFUSIVE CONVECTION PROBLEM IN DOUBLE－DIFFUSIVE SYSTEM

ＰＥＮＡＬＴＹＵＰＷＩＮＤＦＩＮＩＴＥＥＬＥＭＥＮＴＭＥＴＨＯＤＦＯＲＤＩＦＦＵＳＩＶＥＣＯＮＶＥＣＴＩＯＮＰＲＯＢＬＥＭＩＮＤＯＵＢＬＥ－ＤＩＦＦＵＳＩＶＥＳＹＳＴＥＭ￥ＺｈａｎｇＤｉ－ｍｉｎｇ；ＣｈｅｎＨｏｎｇ；ＬｉＬｉｎ（Ｄｅｐａｒｔｍｅｎｔｆ...     

泗阳二站计算机监控系统

根据泵站“无人值班”（少人值守）的要求,在苏北九站计算机监控系统改造成功投运的基础上,介绍了其典型泵站泗阳二站的结构、功能、特点及应用情况。     

ANALYSIS OF STABILITY CHARACTERISTICS OF NONLINEAR FLUID STRUCTURE INTERACTION SYSTEM IN INTERNAL FLOWS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎａｐｉｐｉｎｇｓｙｓｔｅｍｗｉｔｈｉｎｔｅｒｎａｌｆｌｏｗｓ,ａｎｕｎ ｓｔｅａｄｙｏｒｅｘｔｒｅｍｅｌｙｕｎｓｔｅａｄｙｆｌｏｗｉｎｄｕｃｅｄｂｙａｓｕｄｄｅｎｓｙｓｔｅｍｏｐｅｒａｔｉｏｎｏｒｖｉｂｒａｔｉｏｎｍａｙｃｒｅａｔｅａ ｐｒｅｓｓｕｒｅｓｕｒｇｅｃａｌｌｅｄｇｅｎｅｒａｌｌｙｗａｔｅｒｈａｍｍｅｒ.Ａ ｐｒｅｓｓｕｒｅｗａｖｅｐｒｏｐａｇａｔｉｎｇａｌｏｎｇｔｈｅｐｉｐｅｗｉｌｌｉｎｄｕｃｅｓａｎｉｎｔｅｎｓｉｖｅｉｎ ｔｅｒａｃｔｉｏｎｂｅｔｗｅｅｎ…     

STABILITY ANALYSIS OF COUPLED SYSTEM OF MAGNETIC HEAD AND ULTRA-THIN GAS FILM

This paper presents a pressure perturbation equation for the ultra-thin gas film lubrication of magnetic head-disk based on a generalized gas lubrication equation applicable to arbitrary Knudsen number. The gas film pressure of Air Bearing Slider (ABS) was obtained by using the operator-splitting and finite element method. The pressure perturbation equation was solved by the finite element method wit hunstructured triangle grids to calculate the stiffness and damping coefficients of the gas film. Modal analysis of coupled systern of magnetic head and gas film was carried out to obtain natural frequencies, damping rates and mode shapes of the magnetic head vibrations. Vibration stability of Ω-type magnetic head was predicted in this work. Numerical results indicate that the natural frequencies of the coupled system increases as the gas film thickness decreases, and the natural frequencies and damping rate of the coupled vibration modes of heave and piteh motions are much lower than those of uncoupled modes. And it is concluded that the stability of magnetic head is slightly worsened when the disk rotation speed increases.     

A NEW APPROACH TO THE NONLINEAR STABILITY OF PARALLEL SHEAR FLOWS

Lyapunov‘s second method was used to study the nonlinear stability of parallel shear flows for stress-free boundaries. By introducing an energy functional, it was shown that the plane Couette and plane Poiseuille flows are conditionally and asymptotically stable for all Reynolds numbers. In particular, to two-dimensional perturbations, by defining new energy functionals the unconditional stability of the basic flows was proved.     

水电厂设备定期维护信息系统的研究与开发

针对电力企业设备管理的特点，研究和开发了设备定期维护信息系统，提出一种新的产环管理思路。对电力企业特别是已实现无人值班的变电站和“无人值班”（少人值守）的水电厂，如何中强设备定期维护工作的监督和管理，进行了有益的尝试。     

大坳软岩面板堆石坝边坡稳定及应力变形分析

通过对大坳砼面板堆石坝各种坝体分区方案边坡稳定及应力变形分析,在计算分析成果的基础上,合理确定坝体分区.     

THE RANDOM ANALYSIS OF APRON SLAB MISSING STABILITY UNDER WATER JET LASHING

ＴＨＥＲＡＮＤＯＭＡＮＡＬＹＳＩＳＯＦＡＰＲＯＮＳＬＡＢＭＩＳＳＩＮＧＳＴＡＢＩＬＩＴＹＵＮＤＥＲＷＡＴＥＲＪＥＴＬＡＳＨＩＮＧ￥ＣｕｌＬｉ；ＺｈａｎｇＴｉｎｇ－ｆａｎｇ；ＬｉＪｉａｎ－ｃｈｕ；ＺｈｏｎｇＢｉｎｇ（Ｄｅｐｔ．ｏｆＣｉｖｉｌＥｎｇｒｇ．...     

基于扬压力实测资料的古田溪四级大坝稳定分析

针对古田溪四级大坝部分坝段坝基扬压力较大的问题，应用坝基总扬压力模型和概率法对坝基扬压力性态和可能极值进行了分析，由此进一步分析了典型坝段的稳定状况。     

ANALYSIS OF EDL EFFECTS ON THE FLOW AND FLOW STABILITY IN MICROCHANNELS

The effects of the Electrical Double Layer (EDL) on the liquid mean flow and the flow stability in microchannels are investigated by solving the Poisson-Boltzmann equation. The models of the traditional streaming Electrical Current Balance (ECB) and the newly introduced streaming Electrical Current Density Balance (ECDB) are applied to determine the electrical streaming current. The numerical results show that the electrical streaming current backflow in the ECB model near the wall can be removed by using the ECDB model, which is suitable to study the effects of the EDL on the mean flow and the flow stability in microchannels. The flow is found more unstable if the ECDB model is applied.     

WATER HAMMER ANALYSIS OF WATER FEEDING SYSTEM IN COAL FIRED POWER STATION AND ITS INFLUENCE ON THE SAFETY OF OPERATION

In the coal fired power station, the regulation of the load or the sudden stop operation of the unit in accident may result in water hammer, which would have critical influence on the safe operation of the unit. In this paper, the analysis of the water dynamic characters and the calculation of the pressure increment are shown, when the water hammer is produced in the system .     

水电站小波动稳定性分析方法的研究

在传统的小波动稳定分析方法的基础卜,给出基于水力振动理论、考虑水体弹性和机组动态特性的小波动稳定分析方法．结合某实际电站的基本资料,分别在考虑水体弹性和不考虑水体弹性情况下,采用不同的计算方法,研究其小波动稳定性,并进行了比较分析．     

泵站监控系统及其结构的发展趋势

介绍了国内泵站监控系统的概况、泵站监控系统的主要功能和典型的系统结构，阐述并比较了系统结构的2个发展方向，即现地控制单元(LCU)功能增强型泵站监控系统和集控型泵站监控系统，给出了其结构并分析了各自的特点。     

水口水电厂7号机组励磁系统异常分析

简单分析了水口水电厂7号机组励磁系统异常的原因，针对该励磁系统的低励限制环节限制不住励磁电流的现象，阐述了在水口水电厂7号机组进行的多次试验研究和分析结论，包括采用，临时修改低励限制定值和改进励磁装置硬件等方法。在数据分析的基础上，提出了励磁系统的硬件改进措施，并成功应用于同类型的励磁系统，基本上解决了机组存在功率异常摆动的技术难题。     

三峡工程坝区泥沙模型试验测量与控制系统

基于相似理论设计的水利河工模型试验，需要模拟天然的水沙和边界条件，针对三峡工程坝区泥沙模型试验研究的内容，控制系统应用于先进的电子技术、传感技术和计算机硬、软件技术，自动控制模型试验双线船闸充泄水方式和流量，并对模型试验的流速、水位、含水量、波高等数据实施多点同步采集与处理。控制系统功能较完善，软件界面美观新颖，操作简单方便，具有很强的可视性和交互性，已先后成功地应用于三峡工程坝区泥沙模型试验和多项国家重点科技攻关项目，具有推广应用价值。     

SILCO5静止励磁系统灭磁回路的计算和分析

0 引言SILCO5微机静止自并励励磁系统是GE公司比较成熟、可靠性高的定型产品,GE公司将其作为巨型发电机的最理想的配套励磁系统.其主要功能有:最大励磁限制、最小励磁限制、电力系统稳定器、转子过电压保护、发电机转子I2T保护、电压互感器断线保护等.由于其运行可靠、性能优良、功能齐备,国内已有二滩、隔河岩、刘家峡等巨型水电站选用该系统.随着GE公司被三峡工程中标,SILCO5微机静止自并励励磁系统将可能和GE公司的巨型发电机配套,出现在世界上最大的水电站中.但我们通过计算和分析发现,其灭磁回路的设计有较大缺陷.本文以二滩设备为例对此加以分析.     

Siemens S5 PLC及其在水电厂监控系统中的应用

结合龚嘴水力发电厂监控系统改造过程中有关Siemens S5可编程逻辑控制器（PLC）的编程体会，简要介绍了Siemens S5系列PLC的CPU 948R程序的总体结构，讨论了S5 PLC的数据交换和串口编程以及在水电厂监控系统中的应用。