Effect of turbulent flow on the anodic and cathodic kinetics of API X52 steel corrosion in H2S containing solutions. A rotating cylinder electrode study

This work presents the electrochemical kinetics results measured during the corrosion of API X52 pipeline steel immersed in aqueous environments, containing dissolved hydrogen sulfide (H₂S) under turbulent flow conditions. In order to control the turbulent flow conditions, a rotating cylinder electrode (RCE) was used. Five different rotation rates were studied: 0 (or static conditions), 1000, 3000, 5000 and 7000 rpm. It was found that the turbulent flow increases the corrosion rate and the corrosion mechanism for X52 steel exhibits a significant dependence on mass transfer on the cathodic kinetics.     

高喷灌浆技术在福安垸管涌治理中的应用

以福安垸为例，探讨高喷灌浆技术在管涌治理中的应用。在研究工程水文地质和工程地质的基础上，确定施工方案和质量控制措施，质检结果表明，高喷灌浆应用在老管涌险情治理中效果显著，供类似工程借鉴。     

Combination of biological and chemical processes for the treatment of textile wastewater containing reactive dyes

The treatment of a segregated textile wastewater containing reactive dyes was investigated in two continuous‐flow process trains using ozonation and biological processes. The degree of decolorization and dissolved organic carbon (DOC) removal achieved by ozonation followed by aerobic treatment (two‐stage) was compared with that found when an anaerobic and aerobic pretreatment was added (four‐stage). Although the biological pretreatment reduced color by ～70%, similar amounts of ozone were required in both trains to achieve high degrees of overall removal of color and DOC. In both trains, ozonation increased biodegradability in the following aerobic reactor, however, in order to reach ～80% overall DOC removal, a specific ozone absorption (A*) of ～6 gO₃ gDOC_o^?1 was required and >50% of the DOC was mineralized in the ozone reactor. A comparison of cost estimates based on investment and operating costs for the process alternatives showed that a four‐stage train would reduce costs only if it enabled a decrease in A* to less than 2 gO₃ gDOC_o^?1. Difficulties in comparing treatment processes for segregated vs full‐stream wastewaters are discussed. Copyright © 2003 Society of Chemical Industry     

Surface characteristics of titanium with rotary EDM

Experimental investigations have been carried out on electro-discharge machining of titanium in respect of surface finish, out-of-roundness and overcut using rotating copper-tungsten tool electrode. An attempt has also been made to compare the results with stationary electrode. It is concluded that rotation of electrode improves out-of-roundness, surface roughness, overcut and out-of-roundness increase with increase of current with both rotating and stationary electrodes.     

圆筒型混合器中颗粒混合运动的研究

对硅胶颗粒在圆筒型混合器中的混合运动和机理进行了实验研究,分析了填充率、转速等因素对混合过程的影响。研究结果表明:混合过程中颗粒运动的流线不断被拉伸和弯曲,是形成颗粒扩散运动的重要机制;填充率和转速对颗粒的混合运动有明显影响,当填充率不变时,混合效果随混合器转速的提高而提高(接近离心状态之前);当转速不变时,混合效果随填充率增大(不超过70％)而提高。当填充率和转速提高时,颗粒的运动模式由rolling模式向cascading模式发展。     

FLUID FLOW IN ROTATING HELICAL SQUARE DUCTS

1 .　INTRODUCTIONTherotatinghelicalsquareducthasextensive lyapplicationsinengineeringforenhancingtheratesofheatandmasstransfer ,suchascoolingsystemsforconductorsofelectric generatormo tors ,gasturbines ,separation processes .Becauseoftherotation ,theCoriolisforcecanalsocontrib utetothe generationofsecondaryflow ,whichcomplicatestheflowcharacteristics .To gethighperformanceofthesedevices,itisimportanttofindouttheflowcharacteristicsinrotatinghelicalsquareducts .Duetothecomplexityoftheproble…     

基于有限元模型的旋转机械故障诊断方法研究

研究一种对透平机械常见故障进行在线和定量识别的方法。准确预测透平机械在整个转速范围内的振动响应对系统的故障诊断和平衡优化至关重要，然而它依赖于对系统不平衡、对中状态以及支撑系统动力学参数的精确识别。首先引入故障自愈的概念，并用有限元法建立转子-轴承-基础系统动力学方程。然后，根据工程实际，对方程进行简化，并进行了实验研究。结果表明，如果系统在一定转速范围内的振动响应是周期性的，并且轴承处转子的振动是已知的，从理论上能够在线地识别出系统的故障及动力学参数。     

组合滑轮上绳索张力计算及滑轮转动分析

着重推导了组合滑轮上绳索张力公式,并进一步分析了滑轮转动机理,模型简化条件等问题,同时指出了一个常见的组合滑轮转动问题中简化条件的错误.     

任意拉格朗日—欧拉（ALE）法求解三维湍流流动

本文推导了旋转叶轮内流湍流Ｎ－Ｓ方程计算的ＡＬＥ格式。以网格的虚拟运动计算对流作用；采用粘性子循环时步、拉格朗日子循环时步加速收敛；改进上风格式为部分施主单元格式来减小扩散同时实现良好的计算性能；由通量限制控制耗散截断误差；计算中引入短波长阻尼以消除不规则性；以亚网格（ＳＧＳ）湍流模式模拟湍流运动。     

耦合车轮导向机理分析及导向性能对比研究*

不同耦合方式的车轮,其车辆的导向性能有明显不同.建立传统轮对、独立旋转车轮、纵向耦合轮对和弹性阻尼耦合轮对转向架动力学模型,分析其导向机理及纵向蠕滑力的产生,通过仿真确定不同耦合方式车轮车辆的曲线通过规律.计算结果表明传统轮对能够产生同位车轮大小相等、方向相反的纵向蠕滑力且导向能力最优;独立旋转车轮不能产生纵向蠕滑力,通过曲线时只能依靠轮缘进行导向;纵向耦合轮对产生同侧前后大小相等、方向相反的纵向蠕滑力,导向能力优于独立旋转车轮;弹性阻尼耦合轮对产生的纵向蠕滑力规律与传统轮对纵向蠕滑力规律基本一致,其导向性能略差于传统轮对,优于纵向耦合轮对.