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Performance Evaluation of Solar Chimney Draft: Application to Ventilation
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作者 Boukaré Ouedraogo Adama Ouedraogo +2 位作者 Arouna Kabore Kalifa Palm Dieudonné Joseph Bahiebo 《Smart Grid and Renewable Energy》 2024年第4期107-122,共16页
Ventilation is one of the factors contributing to energy consumption in buildings and food preservation. The solar chimney proves to be an alternative for reducing conventional energy consumption. Thus, in this study,... Ventilation is one of the factors contributing to energy consumption in buildings and food preservation. The solar chimney proves to be an alternative for reducing conventional energy consumption. Thus, in this study, the performance of a solar chimney with two active faces for thermally drawing air from a chamber for preserving agri-food products was evaluated. These performances were experimentally assessed through data measurements: temperatures and velocities within the chimney, and their analysis using Excel and MATLAB. The obtained results were compared with those from literature to verify their validity. From this study, it is found that the maximum temperature at the chimney outlet reaches 49.4˚C with an average value of 43.7˚C. Additionally, the heating evolution of the chimney air presents four (04) identical phases in pairs, reflecting the chimney’s operation throughout day. The temperature difference between the outlet and inlet of the chimney reaches a maximum of 17˚C with an average of 12.6˚C. Regarding airflow, the maximum air velocity at the chimney outlet is 0.8 m/s, and the average velocities have consistently been greater than or equal to 0.46 m/s. Thus, it can be concluded that the solar chimney is capable of providing ventilation for the preservation chamber through thermal draft. 展开更多
关键词 Solar Chimney Natural Ventilation Thermal draft AIRFLOW Chimney Effect
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UG/Drafting国标化工程辅助制图软件的研究与实践 被引量:2
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作者 龚雄 赵建军 王启付 《计算机工程与设计》 CSCD 北大核心 2005年第2期473-475,共3页
通过运行于UG/Drafting平台上的国标化工程辅助制图软件(InteCAD)的研究与开发,提出了UG二次开发的系统架构,并对图形对象识别及面向对象的多层图组管理等关键技术进行了详细探讨,对UG及其它平台上的二次开发有一定指导意义,所引入的In... 通过运行于UG/Drafting平台上的国标化工程辅助制图软件(InteCAD)的研究与开发,提出了UG二次开发的系统架构,并对图形对象识别及面向对象的多层图组管理等关键技术进行了详细探讨,对UG及其它平台上的二次开发有一定指导意义,所引入的InteCAD系统可以满足工程制图的实际需要。 展开更多
关键词 UG 制图软件 图形对象 二次开发 面向对象 组管理 CAD 标化 辅助 指导意义
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基于UG/Drafting的国标化工程辅助制图软件
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作者 龚雄 赵建军 《机械工程师》 2004年第7期19-22,共4页
介绍了基于UG/Drafting的国标化工程辅助制图软件(InteCAD),描述了系统的设计思想和主要功能。从使用过程中来看,该软件能够满足工程制图的实际需求。
关键词 计算机应用 UG/drafting 国标化 工程图
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在UG/Drafting中实现格式刷功能
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作者 李如忠 《机械工程与自动化》 2009年第5期181-182,共2页
介绍了利用二次开发技术在UG/Drafting中实现格式刷功能的原理和具体方法,并利用配置文件的方法实现了有选择性的格式刷功能,编制了相应的程序,提高了UG软件的易用性,具有较强的实用价值。
关键词 UG/drafting 格式刷 二次开发
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基于UG/Drafting的公差标注系统开发研究 被引量:2
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作者 庞广智 任家骏 +2 位作者 吴凤林 孙桓五 李颖 《机械管理开发》 2009年第3期148-149,共2页
针对当前UG/Drafting平台公差标注的薄弱环节,提出了公差标注的系统架构,并介绍了框架设计的基本内容;最后利用Visual C++6.0编译器,以UG/OPEN为工具开发了二维公差标注系统。开发的系统可满足工程制图的实际需要,并对UG其他方面的二次... 针对当前UG/Drafting平台公差标注的薄弱环节,提出了公差标注的系统架构,并介绍了框架设计的基本内容;最后利用Visual C++6.0编译器,以UG/OPEN为工具开发了二维公差标注系统。开发的系统可满足工程制图的实际需要,并对UG其他方面的二次开发有一定指导意义。 展开更多
关键词 公差 UG/drafting 二次开发 UG/OPEN
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Draft effect on wave action with a semi-infinite elastic plate 被引量:4
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作者 TENG Bin GOU Ying +1 位作者 CHENG Liang LIU Shuxue 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第6期116-127,共12页
A method for analyzing reflection and transmission of ocean waves from a semi-infinlte elastic plate with a draft is developed. The relation of energy conservation for plates with three different edge conditions ( fr... A method for analyzing reflection and transmission of ocean waves from a semi-infinlte elastic plate with a draft is developed. The relation of energy conservation for plates with three different edge conditions ( free, simply supported and built-in) is also derived. It is found that the present method satisfies the energy relation very well. The effects of draft on wave reflection and transmission coefficients as well as on the vertical vibration of the plates are examined through numerical tests. It is demonstrated that the zero draft assumption works well for low wave frequencies, but the effect of plate draft becomes significant for high wave frequencies. 展开更多
关键词 elastic plate draft water waves INTERACTION REFLECTION TRANSMISSION
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Oblique wave scattering by a semi-infinite elastic plate with finite draft floating on a step topography 被引量:4
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作者 GUO Yunxia LIU Yong MENG Xun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第7期113-121,共9页
On the basis of a potential theory and Euler-Bernoulli beam theory, an analytical solution for oblique wave scattering by a semi-infinite elastic plate with finite draft floating on a step topography is developed usin... On the basis of a potential theory and Euler-Bernoulli beam theory, an analytical solution for oblique wave scattering by a semi-infinite elastic plate with finite draft floating on a step topography is developed using matched eigenfunction expansions. Different from previous studies, the effects of a wave incident angle, a plate draft, three different plate edge conditions (free, simply supported and built-in) and a sea-bottom topography are all taken into account. Moreover, the plate edge conditions are directly incorporated into linear algebraic equations for determining unknown expansion coefficients in velocity potentials, which leads to a simple and efficient solving procedure. Numerical results show that the convergence of the present solution is good, and an energy conservation relation is well satisfied. Also, the present predictions are in good agreement with known results for special cases. The effects of the wave incident angle, the plate draft, the plate edge conditions and the sea-bottom topography on various hydrodynamic quantities are analyzed. Some useful results are presented for engineering designs. 展开更多
关键词 elastic plate draft plate edge conditions matched eigenfunction expansions oblique waves step topography
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CFD-Based Method of Determining Form Factor k for Different Ship Types and Different Drafts 被引量:5
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作者 Jinbao Wang Hai Yu +1 位作者 Yuefeng Zhang Xiaoqing Xiong 《Journal of Marine Science and Application》 CSCD 2016年第3期236-241,共6页
The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low... The value of form factor k at different drafts is important in predicting full-scale total resistance and speed for different types of ships. In the ITTC community, most organizations predict form factor k using a low-speed model test. However, this method is problematic for ships with bulbous bows and transom. In this article, a Computational Fluid Dynamics(CFD)-based method is introduced to obtain k for different type of ships at different drafts, and a comparison is made between the CFD method and the model test. The results show that the CFD method produces reasonable k values. A grid generating method and turbulence model are briefly discussed in the context of obtaining a consistent k using CFD. 展开更多
关键词 form factor computational fluid dynamics(CFD) Prohaska method model test different ship type different draft
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Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant 被引量:4
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作者 Xiaoxiao Li Sam Duniam +3 位作者 Hal Gurgenci Zhiqiang Guan Anand Veeraragavan 侯恩哲 《建筑节能》 CAS 2017年第5期113-113,共1页
Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid a... Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed. 展开更多
关键词 TOWER draft SUPERCRITICAL Rankine LIKELY AMBIENT refined irradiation RENEWABLE Queensland
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NUMERICAL INVESTIGATION OF THE ADVERSE EFFECT OF WIND ON THE HEAT TRANSFER PERFORMANCE OF TWO NATURAL DRAFT COOLING TOWERS IN TANDEM ARRANGEMENT 被引量:2
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作者 符松 翟志强 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2001年第1期24-34,共11页
This article reports the findings on the adverse effect of the crosswind on the performance of natural draft cooling towers through numerical computation with the k-epsilon eddy-viscosity turbulence model. It is obser... This article reports the findings on the adverse effect of the crosswind on the performance of natural draft cooling towers through numerical computation with the k-epsilon eddy-viscosity turbulence model. It is observed here that the cause of the adverse effect of the crosswind on the cooling towers call be attributed to the around flow effect which destroys the radial inflow into the cooling towers when the wind is absent. Hence, a significant deterioration in the heat transfer from the heat exchangers at lateral sides occurs. 展开更多
关键词 natural draft cooling tower buoyancy flow CROSSWIND k-epsilon model
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Draft Consensus Building in Hall for Workshop of Meta-Synthetic Engineering 被引量:2
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作者 XIONG Caiquan LI Dehua JIN Lianghai 《Wuhan University Journal of Natural Sciences》 CAS 2008年第1期45-49,共5页
This paper discusses that there are two sorts of group consensus in Hall for Workshop of Meta-synthetic Engineering: draft consensus and decisive consensus, which are respectively formed in the two synchronous stages... This paper discusses that there are two sorts of group consensus in Hall for Workshop of Meta-synthetic Engineering: draft consensus and decisive consensus, which are respectively formed in the two synchronous stages in the process of "synchronous stages 1- asynchronous stages- synchronous stages 2", and focuses on the concept of draft consensus. Then proposes a draft consensus building model and its solution method called Consensus Building Graph, by which claim concern value, claim support value, claim authority value and claim consensus value can be calculated real time for reaching a consensus, and designs a computer aided consensus building system called Internet based Group Discussion Environment. The model follows the methodology of meta-synthesis from qualitative to quantitative analysis in which computers and humans are combined to solve complex problems. 展开更多
关键词 meta-synthetic brainstorm draft consensus Consensus Building Graph
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Performance Analysis of Induced Draft Fan Driven by Steam Turbine for 1000 MW Power Units 被引量:3
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作者 Jianling Deng Feifei Liang +3 位作者 Yang Ding Zhiping Yang Gang Xu Jizhen Liu 《Energy and Power Engineering》 2013年第4期1387-1392,共6页
Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to redu... Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam. 展开更多
关键词 Induced draft FAN Source Steam AUXILIARY Power Ratio Supply Coal CONSUMPTION Rate INVESTMENT Recovery PERIOD
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Modal analysis of prestressed draft pad of freight wagons using finite element method 被引量:4
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作者 Sachin Sudhakar Harak Satish Chand Sharma Suraj Prakash Harsha 《Journal of Modern Transportation》 2015年第1期43-49,共7页
The present work intends to investigate dynamic behaviour of draft gear using finite element method. The longitudinal force that the draft gear absorbs usually leads to the failure of its components, especially, the l... The present work intends to investigate dynamic behaviour of draft gear using finite element method. The longitudinal force that the draft gear absorbs usually leads to the failure of its components, especially, the load bearing draft pads. Dynamic behaviour of an individual draft pad and a draft gear is determined and characterized with exciting frequen- cies and corresponding mode shapes. The effect of compressive prestress load on the dynamic behaviour of an individual draft pad is also determined as the draft pads in assembled state are under constant axial compressive force in the draft gear. The vibration characteristics of individual draft pad are compared with draft pads that are part of draft gear. The modal analysis gives us a basis for subjecting a draft pad to higher frequency loading for determining its fatigue behaviour. 展开更多
关键词 draft gear. draft pad. Prestress Naturalfrequency Mode shapes Finite element method
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Computer Simulation of Turbulent Flow through a Hydraulic Turbine Draft Tube 被引量:1
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作者 HU Ying CHENG Heming +1 位作者 WANG Quanlong YU Zhikun 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第3期649-652,共4页
Based on the Naviev-Stokes equations and the standard κ-ε turbulence model, this paper presents the derivation of the governing equations for the turbulent flow field in a draft tube. The mathematical model for the ... Based on the Naviev-Stokes equations and the standard κ-ε turbulence model, this paper presents the derivation of the governing equations for the turbulent flow field in a draft tube. The mathematical model for the turbulent flow through a draft tube is set up when the boundary conditions, including the inlet boundary conditions, the outlet boundary conditions and the wall boundary conditions, have been implemented. The governing equations are formulated in a discrete form on a staggered grid system by the finite volume method. The second-order central difference approximation and hybrid scheme are used for discretization. The computation and analysis on internal flow through a draft tube have been carried out by using the simplee algorithm and cfx-tasc flow software so as to obtain the simulated flow fields. The calculation results at the design operating condition for the draft tube are presented in this paper. Thereby, an effective method for simulating the internal flow field in a draft tube has been explored. 展开更多
关键词 hydraulic turbine draft tube turbulent flow numerical simulation
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The Effect of the Operational Parameters on the Draft Requirement of Ripping in a Sandy Clay Soil 被引量:1
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作者 John Ndisya Ayub Gitau +1 位作者 Duncan Mbuge Angela Hiuhu 《Open Journal of Optimization》 2016年第1期1-13,共13页
This study set out to investigate the effect of operational parameters (i.e. ripping depth and operational speed) during a ripping operation on the draft requirement during ripping in a sandy-clay soil. Field experime... This study set out to investigate the effect of operational parameters (i.e. ripping depth and operational speed) during a ripping operation on the draft requirement during ripping in a sandy-clay soil. Field experiments, laboratory tests and numerical modelling techniques were utilised to observe how the draft force varied with changing values of the operational parameters. The discrete element method in the EDEM Academic<sup>TM</sup> software platform was employed to model the soil en-masse to obtain a virtual experimentation platform on which different treatments combing different settings of the operational parameters were investigated. Statistical methods, including ANOVA, regression analysis and the student t-test were applied to establish the significance of the effect of the operational parameters on the draft requirement;statistical analysis revealed that the draft increased linearly with the ripping depth and operating speed suggesting that they are directly proportional. Lower values of the ripping depth and operating speed were found to give the minimum amount of the draft requirement. 展开更多
关键词 draft Requirement Discrete Element Method Numerical Simulation Specific draft Ripping Depth Operational Speed
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Automatic Recognition and Construction of Draft Angle for Injection Mold Design 被引量:1
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作者 Wen-Ren Jong Tai-Chih Li +1 位作者 Yu-Wei Chen Yu-Hung Ting 《Journal of Software Engineering and Applications》 2017年第1期78-93,共16页
In the injection molding process, plastic products are difficult to demold due to friction force between the cavity and products, thus, finished products might be deformed or damaged. Therefore, designers should add a... In the injection molding process, plastic products are difficult to demold due to friction force between the cavity and products, thus, finished products might be deformed or damaged. Therefore, designers should add a draft angle to the geometric surface of products, which is parallel to the unloading direction, in order to help the products eject smoothly from the cavity. This study uses CAD software as the main architecture to develop the function of automatic draft angle recognition and construction. The study is divided into three stages. First, the geometric features of products are identified in the CAD model by induced algorithm, then the quilts to be added in the draft design are determined and classified. Finally, draft angles are created in different ways according to different surfaces. An algorithm suitable for automatic draft recognition and construction, as well as the constraints of automatic creation of draft angle, is proposed. The feature recognition algorithm of this study can automatically inspect 90% of the surfaces to be drafted, and the automatic creation of draft features can economize 80% of required mouse clicks, thus, effectively increasing draft angle design efficiency, and preventing errors in mold design and manufacturing. 展开更多
关键词 INJECTION MOLD DESIGN draft Features DESIGN FEATURE RECOGNITION Automatic DESIGN DFX
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SOLID-LIQUID SUSPENSION SYSTEM IN AGITATED TANK WITH DRAFT TUBE
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作者 程大壮 王英琛 +2 位作者 林猛流 吴德钧 施力田 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1993年第2期23-32,共10页
Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the dist... Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the distance from the inlet to the tank bottom are two importantparameters for draft tube design The NAX-4 impeller,developed in this study,is characterized byits high flow efficiency and low power consumption.Some modifications are made to the Bald′smodel by considering the effects of solid concentration and fluid viscosity on the critical speed forcomplete off-bottom suspension.The modified equation fits the experimental data satisfactority andcan be used in scale-up 展开更多
关键词 SOLID-LIQUID SUSPENSION agitated TANK with draft TUBE SUSPENSION behavior scale-up MATHEMATICAL model
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Pre-drafting Multiple of Spandex for Spandex/cotton Core-spun Yarns
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作者 江慧 彭绍钧 《Journal of Donghua University(English Edition)》 EI CAS 2002年第1期81-83,共3页
The factors that influence the properties of spandex/cotton core-spun yarns are introduced. The pre-drafting multiple of spandex is an important parameter that influences the yarn properties such as elasticity,breakin... The factors that influence the properties of spandex/cotton core-spun yarns are introduced. The pre-drafting multiple of spandex is an important parameter that influences the yarn properties such as elasticity,breaking force, breaking elongation and costs. The experiment with different pre-drafting multiple isdesigned. The effects of pre-drafting multiple on yarn properties are evaluated by fuzzy mathematical decision.3.3 is the optimum pre-drafting multiple for 14.6tex +40D spandex/cotton core-spun yarns. At this multiple,the spandex content is proper and the spandex core is less prone to breakage. The cotton fibers wrap spandex more closely and transfer more frequently between inside and outside. 展开更多
关键词 pre-drafting MULTIPLE YAM properties fuzzy MATHEMATICAL decision.
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Test Research on Influence of Draft on Towing Behaviors of 3-Bucket Foundation Platform
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作者 Le Conghuan Yang Jiayi +1 位作者 Ding Hongyan Zhang Puyang 《Transactions of Tianjin University》 EI CAS 2016年第5期419-425,共7页
To investigate the natural frequencies and towing behaviors of a 3-bucket foundation platform at different drafts, the decay and towing experiments were carried out in a towing tank on a scale of 1:20. The air pressur... To investigate the natural frequencies and towing behaviors of a 3-bucket foundation platform at different drafts, the decay and towing experiments were carried out in a towing tank on a scale of 1:20. The air pressure inside the bucket foundations, the water pressure at the bottom of the bucket foundations, the acceleration of the platform and the towing force were determined in the test process. The time-history curves of the measured parameters were obtained, and the frequency responses of the parameters at different drafts were analyzed by means of fast Fourier transform(FFT). The results showed that the platform natural frequency of heave decreased slightly with the rise of draft. The natural frequencies of roll and pitch are much lower than that of heave, and they increased slightly with the increase of draft. When towing in the following sea, the maximum acceleration of surge, sway and heave has downward trends with the increase of draft, but the change range decreased gradually with the increase of draft. When the draft is 5.0 m(the ratio of draft to bucket height is 0.56), the towing dynamic responses achieve the maximum, which is not conducive to the towing of the platform. When the draft is 6.0 m(the ratio of draft to bucket height is 0.67), the towing dynamic responses are the most stable. 展开更多
关键词 BUCKET FOUNDATION platform draft TOWING behavior model test frequency DOMAIN ANALYSIS time DOMAIN ANALYSIS
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AN INVESTIGATION OF MODELLING ON DRAFTING PROCCES OF WOOLLEN GILL MACHINE
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作者 周旭东 《Journal of China Textile University(English Edition)》 EI CAS 1993年第2期29-33,共5页
The combing process of gill machine is an important link in the wool spinning technology.Inorder to improve the quality of products,it is necessary to study the new autoleveling device whichuses the modern control the... The combing process of gill machine is an important link in the wool spinning technology.Inorder to improve the quality of products,it is necessary to study the new autoleveling device whichuses the modern control theory and microcomputer science.We have to set up a mathematicalmodel for object:As the woolen yarns (both input and output) are complex random process,it issuitable for CARMA (controlled autoregressive-moving average) to describe the object by meansof time series analyses of models. 展开更多
关键词 Wool spinning machinery GILLING MACHINE identification draftING process AUTOLEVELLER time series analyses.
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