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针对一个并联式涡轮基组合循环(Turbine Based Combined Cycle, TBCC)发动机排气系统的气动方案,对其在整个飞行包线范围内典型工作点上的流场进行了数值模拟研究,获得了飞行包线范围内排气系统相应的推力系数、升力、俯仰力矩随飞行马赫数的变化关系。计算结果显示,在整个飞行包线范围内,排气系统的轴向推力系数随着飞行马赫数先减小后增大,在跨声速飞行时降到最低 Ma=0.9,涡喷不加力时为0.562,加力时0.662),在设计点附近达到最大;升力和俯仰力矩性能在亚声速及跨声速飞行时较差,在超声速飞行时随着飞行马赫数增加逐渐好转。表明排气系统在跨声速飞行范围内工作时应采取措施以改善其性能。 相似文献
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CLR反应器是在IC反应器的基础上优化的厌氧反应装置,详细介绍了改进的工艺和实验方案,对垃圾焚烧发电厂产生的渗滤液,采用CLR厌氧反应器进行实验研究,结果表明:在中温的环境下,CLR厌氧进水COD从4 200 mg/L逐渐提高到42 000 mg/L的情况下,并稳定进水COD浓度42 000 mg/L左右时,出水COD在8 400 mg/L左右,COD去除率为80%以上.CLR反应器处理实际渗滤液的负荷能够达到42 kgCOD/(m3·d),产气效率为0.4L沼气/gCOD,从处理效果的分析为生产规模工程设计提供参考. 相似文献
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Gauthier F Giraud L Bournival S Bourbonnière R Richard JG Daigle R Massé S 《Journal of Safety Research》2007,38(1):35-51
INTRODUCTION: Companies that use forklifts to load and unload trucks at loading docks are well aware of the main danger associated with this type of activity (i.e., the possibility of the forklift falling or tipping over when the truck suddenly moves away from the dock). Even if various truck restraint measures can be implemented to reduce the possibility of this type of accident, a number of hazardous incidents that result in a forklift tipping over from a loading dock still do occur regularly in day-to-day activities. This situation has brought experts to examine and evaluate the effectiveness of different measures and systems depending on the context in which they are used. METHODS: The present study touched upon both the technical and the organizational aspects of the restraint measures that could have an impact on safety. Certain elements were examined very closely, especially the failure of mechanical devices and their relation to the environment in which they are used, as well as the systemic interaction between people and the various restraint measures in use in a given context. CONCLUSION: This article presents a safety evaluation tool regarding restraint measures or systems for trucks docked at loading platforms - a tool that, of course, would take into consideration both the specific contextual aspects related to the docking bay itself, and to the plant. IMPACT ON INDUSTRY: This tool is designed to help companies choose the optimal safety measures to implement, while remaining realistic in terms of the technical and economic aspects of any given situation. 相似文献
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曳引驱动电梯上应装设符合要求的轿厢上行超速保护装置,使轿厢制停或使轿厢速度降低至对重缓冲器能够承受的设计范围内,防止“冲顶”事故。本文阐述了上行超速保护装置的设置历程,概述了上行超速保护装置的构成及现状,分析失效原因,提出检验方法。在此基础上指出检验过程中面临的问题,认为缺乏统一定性定量的试验方法及判别标准是目前亟待解决的问题关键,提出了相应的改善建议。 相似文献
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安全阀型式试验数据采集系统结合安全阀开启高度与其他性能指标的关系,创新性地将开启高度、压力和流量三组数据整合到同一个曲线监控图中分别显示,根据开启高度的不同状态读取相应试验数据.从而得到安全阀各项性能指标。 相似文献
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In order to simulate the motion of bubbles, drops, and particles, it is often important to consider finite Reynolds number
effects on drag, lift, torque, and history force. Herein, an equation of motion is developed for spherical particles with
a no-slip surface based on theoretical analysis, experimental data, and surface-resolved simulations. The equation of motion
is then extended to account for finite particle size. This extension is critical for particles which will have a size significantly
larger than the grid cell size, particularly important for bubbles, and low-density particles. The extension to finite particle
size is accomplished through spatial-averaging (both volume-based and surface-based) of the continuous flow properties. This
averaging is consistent with the Faxen limit for solid spheres at small Reynolds numbers and added mass and fluid stress forces
at inviscid limits. The finite Re
p
corrections are shown to have good agreements with experiments and resolved-surface simulations. The finite size corrections
are generally fourth-order accurate and an order of magnitude more accurate than point-force expressions (which neglect quadratic
and higher spatial gradients) for particles with size on the order of the gradient length-scales. However, further work is
needed for more quantitative assessment of the truncation terms and the overall model robustness and accuracy in complex flows. 相似文献
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Nir Keren Sumit Anand M. Sam Mannan 《Journal of Loss Prevention in the Process Industries》2006,19(6):714-718
Currently, failure-based risk assessments in the process industry do not empirically take into account the type of chemicals processed in equipment, mainly because chemical-specific failure rate data barely exist. This paper suggests a methodology to calibrate failure-based risk assessment predicated on the chemical being processed in equipment. The methodology uses a data mining tool known as the association rule. Specifically, the lift association rule is utilized (the Lift Methodology). By extracting equipment failure information from incident databases based on the chemical involved in the process, the Lift Methodology leads to more accurate equipment-related risk assessment. 相似文献
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汪友杰 《中国特种设备安全》2014,(8):29-32
钢丝绳是电梯重要的载重元件,直接关系着电梯能否安全运行。维保公司在日常维护保养过程中一定要按照规定的钢丝绳保养方法进行维护。通过分析钢丝绳被违规添加黄油润滑、干燥生锈两种情况下的曳引力,对正确维护保养钢丝绳提出建议。 相似文献
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