检索结果-南通市图书馆

Analysis of Flight dynamics characteristics of Tilt Quad Rotor with Partial Tilt-Wing

Transactions of Nanjing University of Aeronautics and Astronautics 2019年第6期36卷 938-951页

作者： WANG Zhi gang DUAN Dengyan YANG Yongwen YU Hongrui LI Jianbo National Key Laboratory of Science and Technology on Rotorcraft Aerodynamic College of Aerospace EngineerngNanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China Yangzhou Collaborative Innovation Research Institute Shenyang Aircraft Design&Research InstituteYangzhou 225000P.R.China

The aerodynamic model of propeller,wing,fuselage and vertical tail are established for the tilt quad rotor(TQR)with partial tilt-wing,and then the flight dynamic model is *** on the six-degree-of-freedom equation and the small disturbance linearization assumption,the trimming and stability of the tilt quad rotor with partial tilt-wing and the tilt quad rotor without tilt-wing are *** results show that in the hovering state,due to the existence of tilt-wing,the propeller wake reduces the downwash on the wing,thereby reducing the vertical weight gain of the *** is beneficial to increase the endurance time and improve the endurance *** transition corridor of the TQR with tilt-wing is narrower than that of the TQR without tilt-wing,but the transition corridor of TQR with tilt-wing still has a large space for ***,the stability analysis shows that the Dutch roll damping ratio is larger,and in other modes the aircraft has a certain *** manipulation response analysis shows that in the transition mode the lateral-directional coupling is strong.

关键词： dynamics characteristics tilt quad rotor stability manipulation response

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Labyrinth seal leakage and dynamics characteristics analysis based on Black Model

引用

Journal of Harbin Institute of Technology(New Series) 2012年第1期19卷 58-62页

作者：马文生陈照波焦映厚沈那伟 School of Mechatronics Engineering Harbin Institute of Technology Rotor dynamics Laboratory Virginia TechBlacksburgVA 24061USA

One of the important problems to be tackled in turbo machines is the leakage dynamics characteristics of labyrinth seals. In this paper we analyzed the effect of labyrinth seal structure and the change in fluid flow pressure on the leakage characteristics of seal. Computational fluid dynamics (CFD) model for 3D labyrinth seal was built which provides a basis for reducing steam flow excitation. The streamline pattern and the pressure drop characteristics for leakage of steam through a labyrinth seal was investigated. Simulations of internal flow and leakage characteristics had been performed by CFD software and Black-Child model. The results showed that the amount of leakage is directly proportional to the tooth gap and inlet pressure and inversely proportional to the cavity depth and outlet pressure. The proposed CFD model provides a feasible method to predict the leakage characteristics of labyrinth seal in response to the structure of seal and the change in inlet-outlet pressures.

关键词： labyrinth seal leakage black-child model dynamics characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Separate Control of High Frequency Electro-hydraulic Vibration Exciter

引用

Chinese Journal of Mechanical Engineering 2011年第2期24卷 293-302页

作者： JIA Wen＇ang RUAN Jian REN Yan The Key Laboratory of Mechanical Manufacture and Automation of Ministry of Education Zhejiang University of Technology Hangzhou 310032 China

The working frequency of the conventional electro-hydraulic vibration exciters,which consist of a servo valve and a hydraulic cylinder,is generally restricted within a narrow range due to limited frequency response capability of the servo valve *** counteract such restriction,a novel scheme for an electro-hydraulic vibrator,controlled by a two-dimensional valve（2D valve） and a bias valve in parallel,is therefore *** frequency,amplitude and offset are independently controlled by rotary speed,axial sliding of the spool of the 2D valve and axial sliding of the spool of the bias *** principle of separate control was presented and the regulation approach of frequency,amplitude and offset was discussed.A mathematical model of the hydraulic power mechanism for the proposed vibration exciter was established to investigate the relationship between the amplitude and the axial sliding of the 2D valve＇ spool,as well as that between the offset and the axial sliding of the bias valve＇s spool at various *** experimental system was built to validate the theoretical *** is verified that the 2D exciter is capable of working smoothly in a frequency range of 5- 200 *** its frequency,amplitude and offset can be controlled respectively by either closed loop or open loop *** is a linear relationship between the output amplitude and the spool axial opening of the 2D valve until a point when the flow rate becomes saturate and the amplitude remains *** offset displacement of the cylinder＇s piston is linearly proportional to the axial displacement of the spool of the bias valve,when the valve opening is less than 25%.Thereafter,the slop of the offset curve decreases and tends to *** proposed electro-hydraulic vibration controlled by the 2D valve not only facilitates the realization of high-frequency electro-hydraulic vibration,the high-accuracy of vibration can also be achieved by means of independent controls to the freque

关键词： control valves electro-hydraulic system vibration exciter dynamics characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Full-scale monitoring of typhoon effects on a super-tallest building

Full-scale monitoring of typhoon effects on a super-tallest ...

引用

第十四届全国结构风工程学术会议

作者： Alex To Ove Arup and Partners

＜正＞This paper presents the field measurement results of wind effects on the tallest tall building in Hong Kong during the passage of Typhoon Molave on July 18 and July 19,*** field data such as wind speed,wind direction,wind pressure,and dynamic responses were simultaneously and continuously recorded from a comprehensive monitoring system installed in the *** analysis of the measured field data was carried out to investigate the wind effects on the super-tall *** characteristics of the typhoon-generated wind including turbulence intensity,gust factor,turbulence integral length scale and power spectral density of fluctuating wind speed were *** dynamic properties of the building were also determined based on the *** damping ratios of the building were evaluated by random decrement technique,which demonstrated amplitude-dependent characteristics and increased with increasing amplitude of the building during the *** results of this field study supplement existing databases by providing valuable information on the wind effects on super-tall buildings.

关键词： field monitoring wind-induced vibrations dynamics characteristics wind effect tall building

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：