关于过程管理在流体力学教学中应用的思考     

李峰 《科教文汇》2014,(33):58-59

流体力学是关于流体机械运动规律及其应用的一门学科,它主要是研究流体之间的相互力的作用,包括流体与流体、壁面与流体、流体与其他等方面。流体力学是一门与人类生活息息相关的学科,并且众多理工学科的基本专业知识都是流体力学,它所包含的理论知识和实验对于专业课学习、学生毕业设计、实际工程问题等起着重要的理论支撑和指导作用。所以流体力学的教学在工科高等院校显得尤为重要。  相似文献   

Unsteady flow phenomena in human undulatory swimming: a numerical approach     

Steffen Pacholak  Stefan Hochstein  Alexander Rudert  Christoph Brücker 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):176-194

The undulatory underwater sequence is one of the most important phases in competitive swimming. An understanding of the recurrent vortex dynamics around the human body and their generation could therefore be used to improve swimming techniques. In order to produce a dynamic model, we applied human joint kinematics to three-dimensional (3D) body scans of a female swimmer. The flow around this dynamic model was then calculated using computational fluid dynamics with the aid of moving 3D meshes. Evaluation of the numerical results delivered by the various motion cycles identified characteristic vortex structures for each of the cycles, which exhibited increasing intensity and drag influence. At maximum thrust, drag forces appear to be 12 times higher than those of a passive gliding swimmer. As far as we know, this is the first disclosure of vortex rings merging into vortex tubes in the wake after vortex recapturing. All unsteady structures were visualized using a modified Q-criterion also incorporated into our methods. At the very least, our approach is likely to be suited to further studies examining swimmers engaging in undulatory swimming during training or competition.  相似文献   

Computational fluid dynamics (CFD) modeling of microclimate for salts crystallization control and artworks conservation     

《Journal of Cultural Heritage》2014,15(4):448-457

Many deterioration processes are linked to unsuitable microclimatic condition in cultural buildings. One of the most diffused processes is soluble salts crystallization that can be accelerated in masonry structures within specific microclimatic values for different chemical compounds. In this paper, microclimate and efflorescence diffusion were monitored over a one-year period in the Crypt of the Cathedral of Lecce (South Italy). This allowed to relate the microclimate with the efflorescence variation over time. A three-dimensional computational fluid dynamics (CFD) model was then developed to detail the thermo-hygrometric parameters and airflow patterns responsible for salts crystallization and artworks deterioration. Two main conditions were reproduced; one to simulate the current microclimate, which simulations showed to be inadequate for conservation, and the other to search for a more appropriate solution. In both cases, summer and winter conditions were simulated and compared to find a microclimate able to ensure more suitable thermo-hygrometric intervals required by the constituting artworks materials. The results helped to suggest actions to improve maintenance of the Crypt.  相似文献   

Study of adenosine deaminase activity in various arthritic conditions     

R. Kumar  S. B. Pachori  G. K. Senger  Satyanand  L. D. Joshi 《Indian journal of clinical biochemistry : IJCB》1994,9(2):72-74

Aim of present study was to compare the adenosine deaminase (ADA) activity in various types of arthritis conditions with synovial effusion. No. significant difference was observed in ADA activity in serum of control and study groups but results have shown a definite pattern of ADA activity in synovial fluid in various arthritic conditions. The highest value of ADA activity was observed in synovial fluid of patients with tubercular arthritis followed by rheumatoid, septic, osteo and post traumatic arthritis. Thus measurement of ADA activity in synovial fluid can be used as a parameter of differential diagnosis of arthritis specially tubercular in initial stages.  相似文献   

多元文化背景下的自我价值与身份建构——论任碧莲的《典型的美国佬》     

魏琴 《青海师范大学学报(哲学社会科学版)》2011,33(6):98-101

当代华裔女作家任璧莲的成名作《典型的美国佬》被认为是新一代华裔美国文学的代表作。小说着意刻画了多元文化背景下人物的身份问题并对其进行了新的诠释。本文主要是通过分析主人公自我的体现,即对中国传统价值的认同和对美国梦的不同理解与追求方式,来探讨自我与美国梦对人物流动身份的影响,同时关注了作品开放式结局的寓意所在。  相似文献   

皮划艇桨叶流体动力分析研究     

刘东升  朱英民 《吉林体育学院学报》2011,27(1):83-84

皮划艇在水中的运动是通过人的划桨动作推动船向前进,而皮划艇所获得的动力都与桨叶的流体动力性能有关,它直接影响着船速的变化。论述了流体力学在皮划艇项目中的应用现状,为我国的体育流体力学的发展提供借鉴,为设计高性能水上运动器材奠定基础,为皮划艇运动训练起到积极的指导作用。  相似文献   

淖尔套矿区小口径施工工艺     

张吉鹏  王洪伟  董强 《中国科技信息》2011,(11):80-80

淖尔套矿区施工解决两大问题：第一覆盖层厚达400米,套管的合理级配及安放。第二孔内涌水的解决,保证钻孔内冲洗液也不被地下水侵蚀,冲洗液的稳定是成孔关键要素之一。  相似文献   

二切线火切机光栅定尺系统的实现     

郗宏刚 《科技风》2011,(19):127

二切线板坯火切机,是用于把倍尺坯切割成定尺坯的设备,其定尺系统的准确程度决定了产品的切割精度。罗泾厚板厂的BⅡG-15型火切机,其定尺系统采用CCD摄像定尺方式,设计精度为<15mm,实际使用中的精度为-15mm到+30mm之间。本文对现有CCD定尺系统的不足之处进行了分析,并介绍了能够提高设备定尺精度的光栅定尺系统的实现。  相似文献   

流体力学北京市级实验教学示范中心建设     

隋秀香  李春兰  阎凤元 《实验室研究与探索》2014,33(9):158-161

中国石油大学(北京)流体力学实验教学示范中心是北京市市级实验教学示范中心,经过多年的发展,中心已经成为开展科学研究的重要平台,成为培养石油专门人才的重要基地。现结合中国石油大学(北京)流体力学实验教学示范中心经验,本着"学生为本、强化基础、鼓励创新、结合专业、重视应用"的教育指导方针,从建设教学团队、改进实验教学方法、培养学生能力、促进科研与教学相结合等方面,探讨石油高校流体力学实验教学的建设。  相似文献   

CFD simulation of micro-particle trapping under water tweezers     

Xin-Hua Yi  ;Xiao-Min Cheng  ;Feng-Lian Niu  ;Hong-Chao Fan 《上海大学学报(英文版)》2014,(3):259-264

In early research, capture and manipulation of particles were mainly achieved by means of light, electricity and plasma in micro-fabficaton and micro-assembly. A new method is proposed using micro-water jet to form water tweezers to capture solid particles and implement position control of micro-particles. This paper analyzes the basic prin- ciple of water tweezers, and the discrete element method and smoothed particle hydrodynamics method are employed to establish a solid-liquid coupling model used in analyzing the trapping mechanism. A flow field model is set up to simulate dynamic characteristic of water tweezers based on computa- tional fluid dynamics （CFD）. Selection of boundary conditions, initial guess, solver control and convergence strategies of the model are discussed. Velocity and pressure of streamline are predicted and discussed under certain input conditions. Simu- lation results demonstrate that it is an efficiently theoretical method to eventually trap solid particles by water tweezers.  相似文献