关键词： computational fluid dynamics   clean aviation   aerodynamics   propulsion   high-performance computing  

摘要： As global air travel expands rapidly to meet demand generated by economic growth, it is essential to continue to improve the efficiency of air transportation to reduce its carbon emissions and address concerns about climate change. Future transports must be 'cleaner' and designed to include technologies that will continue to lower engine emissions and reduce community noise. The use of computational fluid dynamics (CFD) will be critical to enable the design of these new concepts. In general, the ability to simulate aerodynamic and reactive flows using CFD has progressed rapidly during the past several decades and has fundamentally changed the aerospace design process. Advanced simulation capabilities not only enable reductions in ground-based and flight-testing requirements, but also provide added physical insight, and enable superior designs at reduced cost and risk. In spite of considerable success, reliable use of CFD has remained confined to a small region of the operating envelope due, in part, to the inability of current methods to reliably predict turbulent, separated flows. Fortunately, the advent of much more powerful computing platforms provides an opportunity to overcome a number of these challenges. This paper summarizes the findings and recommendations from a recent NASA-funded study that provides a vision for CFD in the year 2030, including an assessment of critical technology gaps and needed development, and identifies the key CFD technology advancements that will enable the design and development of much cleaner aircraft in the future.

关键词： 储层流体   高温高压环境   设备公司   压井   石油公司   威德   流体分析   分析仪器   合作设计   操作温度  

摘要： 美国Weatherford(威德福国际有限公司)是较著名的油田服务和设备公司,他们与石油公司合作设计和开发了全新的可用于高温高压井下的多通道光电分析仪器,命名为储层流体分析仪(RFA)。该技术的核心设备是一个直径可达11.43cm(4.5英寸)的传感器,能够对井下4 828m(3英里)范围内的储层流体进行分析。在线功能的RFA可以实现对储层流体类型和组成的实时、原位刻画。

标准号: HB 6167.9-2014

摘要： 本部分规定了民用飞机机载设备流体污染试验条件和试验方法。本部分适用于民用飞机上安装在经常受到流体污染位置上的机载设备。

关键词： 液滴体积测量   微流体系统   图像处理   CCD相机   Canny算子  

摘要： 为实现微机电系统(MEMS)微液滴体积的快速准确实时测量,提出基于图像处理技术的微液滴体积测量方法。首先,采用数字显微镜系统对微流控系统的微液滴进行图像采集,然后对原始图像进行数据分析和处理,最后进行维纳滤波、图像侵蚀、边缘提取,通过Canny算子选择高斯滤波器平滑处理后的图像,得出液滴的直径,进而计算出液滴体积。试验结果表明该方法用于微液滴体积测量是可行有效的。

关键词： 微机电系统   微流体   传感测试平台   流动特性   细胞培养  

摘要： 微流体系统作为一种可对流体进行精密控制、操作与检测的技术,其发展为细胞体外培养提供了新的平台,而且可与生物传感器结合构成微流体传感测试系统,大大提高细胞传感检测的精确性、一致性和稳定性。在微系统设计与制造的基础上,提出了一种新型微流体系统结构,应用COMSOL软件建立了微流体系统模型,通过对其流动特性的分析对比,优化了系统结构,系统地研究了其对细胞培养与检测的影响。结果表明:该结构既能实现细胞的长期培养;又能通过精确的微流控制,结合生物传感器,对不同时期或不同病态的细胞进行实时检测和分析。该研究对医用药物测试芯片与微流传感测试系统有着重要的意义。

关键词： jet   jet ratio   jet angle   multiple objectives   nonlinear genetically optimized coupled inversion  

摘要： Optimal dilution and the lowest possible energy consumption are essential environmental and economic objectives for deep sea sewage discharge. In this paper, a new method with multiple parameters and objectives, nonlinear, genetically optimized and coupled inversion for determining jet ratios and angles was established by coupling Genetic Algorithms (GAs) with Anisotropic Turbulent Buoyant Jet Models with variable densities to achieve these objectives. The multiple objectives were taken into account for the jet model and the Operation Energy Consumption Equation was input into the GAs. Real coding methodology was utilized to avoid the precision losses of binary coding. A multiple parameters matching designed cases methodology was used to improve the convergence velocity. The fluctuated convergence curves that were utilized for searching for the optimal multiple parameters showed that the present method is suitable for the multiple objectives optimizing inversion problem. The numerical results of the re-calibrations and comparisons showed that the multiple parameters and objectives, nonlinear, genetically optimized and coupled inversion method has the advantages of improving the jet's water mixing efficiency with environmental waters, while also reducing the energy consumption. The optimal multiple parameters of a jet ratio of 4, and a jet angle of 90 degrees, satisfy the demands of the multiple objectives.

关键词： Alzheimer disease   Preclinical Alzheimer's disease   Early detection   Cholinergic   Cognition   Biomarkers   Diagnosis   Anticholinergic drugs   Scopolamine   beta-Amyloid protein  

摘要： Background: Abnormal beta-amyloid (A beta) is associated with deleterious changes in central acetylcholinergic tone in the very early stages of Alzheimer's disease (AD), which may be unmasked by a cholinergic antagonist. We aimed to establish an optimal "microdose" of scopolamine for the development of a "cognitive stress test." Methods: Healthy older adults (n = 26, aged 55-75 years) with two risk factors for AD, but with low cortical A beta burden, completed the Groton Maze Learning Test (GMLT) at baseline and then received scopolamine (0.20 mg subcutaneously). Participants were reassessed at 1, 3, 5, 7, and 8 hours postinjection. Results: There were significant differences, of a moderate magnitude, in performance between baseline and 3 hours postinjection for total errors, rule break errors, and the GMLT composite (d approximate to 0.50) that were all unrelated to body mass. Conclusions: A very low dose of scopolamine leads to reliable cognitive impairment at 3 hours postdose (T-max) and full cognitive recovery within 5 hours, supporting its use as a prognostic test paradigm to identify individuals with potential preclinical AD. This paradigm is being implemented in a larger cohort of healthy adults, with high or low A beta, to identify pharmacodynamic differences between groups. (C) 2014 The Alzheimer's Association. All rights reserved.

关键词： 微流体系统   微开关   水银开关  

摘要： 本文对新型基于水银为介质的微流体加速度开关进行了理论可行性分析研究。在理论上说明了水银加速度开关的原理。对于在不同加速度作用下,水银运动的方程进行了理论探索,这对于整个开关的研究具有重要意义。

关键词： 微重力   蓄液器   流体管理   落塔试验  

摘要： 为验证板式贮箱蓄液器的蓄液性能,搭建了蓄液器模型试验系统,针对蓄液器模型的蓄液性能和流体传输行为进行微重力落塔试验研究,得到微重力环境下蓄液器的流体蓄留和传输规律.试验结果表明,相对于楔形蓄液器,双圆锥形蓄液器具有更好的蓄液能力,对于双圆锥形蓄液器,承受侧向加速度时仍具有良好的蓄液能力,合理设计蓄液器结构可有效地蓄留液体并控制液体传输速度.该试验成果不仅为新型板式流体管理部件设计优化提供参考,同时也为空间环境下流体控制提供了一种新方法.

关键词： 光力学   液体   微流体系统   美国科学家   玻璃毛细管   大学  

摘要： 美国科学家利用光力学成功地探查了微流体系统。Kyu Hyun Kim及其在密歇根大学和伊利诺伊大学香槟分校的同事 研制了一种球形空心玻璃毛细管，用糖水梅液填充后，