Three-dimensional numerical simulation of a vertical axis tidal turbine using the two-way fluid structure interaction approach     

Syed-shah KHALID  Liang ZHANG  Xue-wei ZHANG  Ke SUN 《浙江大学学报(A卷英文版)》2013,14(8):574-582

The objective of this study was to develop, as well as validate the strongly coupled method （two-way fluid structural interaction （FSI）） used to simulate the transient FSI response of the vertical axis tidal turbine （VATT） rotor, subjected to spatially varying inflow. Moreover, this study examined strategies on improving techniques used for mesh deformation that account for large displacement or deformation calculations. The blade＇s deformation for each new time step is considered in transient two-way FSI analysis, to make the design more reliable. Usually this is not considered in routine one-way FSI simulations. A rotor with four blades and 4-m diameter was modeled and numerically analyzed. We observed that two-way FSI, utilizing the strongly coupled method, was impossible for a complex model; and thereby using ANSYS-CFX and ANSYS-MECHANICAL in work bench, as given in ANSYS-WORKBENCH, helped case examples 22 and 23, by giving an error when the solution was run. To make the method possible and reduce the computational power, a novel technique was used to transfer the file in ANSYS-APDL to obtain the solution and results. Consequently, the results indicating a two-way transient FSI analysis is a time- and resource-consuming job, but with our proposed technique we can reduce the computational time. The ANSYS STRUCTURAL results also uncover that stresses and deformations have higher values for two-way FSI as compared to one-way FSI. Similarly, fluid flow CFX results for two-way FSI are closer to experimental results as compared to one-way simulation results. Additionally, this study shows that, using the proposed method we can perform coupled simulation with simple multi-node PCs （core i5）.  相似文献   

Three Different Methods of Calculating Vertical Jump Height from Force Platform Data in Men and Women     

Gavin L. Moir 《Measurement in physical education and exercise science》2013,17(4):207-218

The purpose of the present study was to investigate the effects of different methods to calculate vertical jump height in men and women. Fifty men and 50 women performed three countermovement vertical jumps for maximal height on a force platform, the highest of which was used in the statistical analyses. The peak displacement attained by the center of mass (COM) during flight was obtained from three different calculations: (1) using the time in the air (TIA), (2) using the vertical velocity of the COM at take-off (TOV), and (3) adding the positive vertical displacement of the COM prior to take-off to the height calculated using TOV (TOV+s). With all calculations, men produced significantly greater jump heights than women (p < 0.05). TIA produced significantly greater jump heights than TOV in men and women, while TOV+s produced significantly greater jump heights than both TIA and TOV in men and women (p < 0.05). Despite these differences, the methods produced consistent results for both men and women. All calculation methods have logical validity, depending upon the definition of jump height used. Therefore, the method used to calculate jump height should be determined by the equipment available to the practitioner while giving consideration to the sources of error inherent in each method. Based upon the present findings, when using a force platform to calculate vertical jump height, practitioners are encouraged to use the TOV method.  相似文献   

多元函数重极限的几种求法     

翟明娟 《长治学院学报》2003,20(2):50-51

文章给出 8种多元函数重极限的解法  相似文献   

数学课的新理念     

武丽霞 《中国教育发展研究杂志》2007,4(4):24-26

文章从不同角度阐述数学课新理念在实际教学中的几种表现，主要有提高学生的主动性和创造力，建立学生互动、互助平台，关注学生之间的差异，利用现代化的教学手段生动数学课堂气氛，要注意肯定、赞美学生，激发学生学习的内因，还原学生是学习主体的真正位置．  相似文献   

一种用于数字高清晰度电视的内插法     

黄旭红 《闽江学院学报》2006,27(5):88-91,118

通过对数字高清晰度电视分析和对现有扫描变换技术的比较,提出一种全新的方法——垂直瞬间3场调节内插法,并采用DH-CG410视频采集卡对其进行了仿真验证．该方法比一般的线性内插法具有更好的图像质量,与自适应运动检测控制内插法、基于小波变换的自适应内插法等方法相比,方法更简便易行．  相似文献   

论当代青少年的社会化缺失——从生于1980年的一代谈起     

刘永明 《河西学院学报》2005,21(1):90-92

青少年从传统上与社会隔离到主动疏离于社会,割断了真实社会化与虚拟社会化的连续性,垂直约束减弱,横向的平等关系和力量关系适应困难。建立包含或超越多元价值观的社会化标准,确立相对稳定的、明确的社会规范和价值观念,诉诸一种整合机制,以期规范信息社会的行为是必须和有效的。  相似文献   

折射定律在中国的早期传播     

李海 《雁北师范学院学报》1996,(3)

近代光学知识在中国的早期传播中,传入最完整的光学知识是折射定律。明未清初,由耶稣会士先传入关于折射现象的描述;鸦片战争以后,中外学者合作译著《光论》、《光学》两书,折射定律得以准确的传入。  相似文献   

Field investigation on effects of railway track geometric parameters on rail wear   总被引：2，自引：0，他引：2  

SADEGHI J AKBARI B. 《浙江大学学报(A卷英文版)》2006,7(11):1846-1855

INTRODUCTION Among the numerous components used in the railway industry for high axle load operations, wheels and rails comprise a major source of running expen- diture. The wheel/rail interaction is the main technical factor determining design procedures and mainte- nance and replacement schedules for both vehicle and track. The rail wear is one of the most important factors causing reduction of the railway track life cycle. The re-profiling and replacement of worn wheels and rails is re…  相似文献   

反垄断法视野中的买断式销售行为     

陈智能  蔡新艺 《宜宾学院学报》2006,6(3):15-17

买断式销售以生产商和销售商达成买断销售协议为基础。买断销售协议属于反垄断法中的纵向限制竞争行为。我国对买断销售行为应加以立法规制,建立以合理分析为原则,以市场结构标准为主要考察目标的规制买断式销售行为的法律制度。具体市场结构标准的确定,依赖于我国政策和经济发展不同阶段的需要,并由反垄断法执法机关在实践中不断地作出调整。  相似文献   

水稻插秧机纵向送秧机构分析     

张加清  王琛 《金华职业技术学院学报》2002,2(3):41-42

本文介绍了机动水稻插秧机纵向送秧机构的基本结构、工作原理和设计要求，分析了各种纵向送秧机构的特点及其对插秧质量的影响，为纵向送秧机构的合理设计提供了依据。  相似文献