检索结果-内蒙古大学图书馆

Numerical studies of the effects of design parameters on flow fields in spiral concentrators

INTERNATIONAL JOURNAL OF COAL PREPARATION AND UTILIZATION 2022年第1期42卷 67-81页

作者： Ye, Guichuan Ma, Liqiang Alberini, Federico Xu, Qian Huang, Gen Yu, Yuexian China Univ Min & Technol Beijing Sch Chem & Environm Engn Beijing 100083 Peoples R China Univ Birmingham Sch Chem Engn Birmingham W Midlands England Univ Sci & Technol Beijing Sch Energy & Environm Engn Beijing Peoples R China Taiyuan Univ Technol Coll Min Engn Taiyuan 030024 Peoples R China

Spiral concentrators are widely used for the concentration of coal and heavy minerals. The design for the spiral concentrator is full of challenge because of the sensitivity of design parameters to water flow field. The study aims to reveal the rule of the design parameters on water flow field in spiral concentrators. The pitch, the transverse angle, and the flow rate were taken as the variables. A suggested simulation method based on grid independence investigation, four types of turbulence models, and Volume of Fluid (VOF) approach was proposed. The water flow field on spirals with different design parameters was determined by the validated model. The predicted water flow depth show agreement with the measured results. The Reynolds-Stress Model (RSM) turbulence model is superior to other turbulence models. The water depth and the primary velocity in spiral concentrators increase smoothly outward. The secondary velocity is relatively small compared with the primary velocity. No obvious secondary flow exists in the inner trough. The reversal position of the secondary flow is approximate at the fractional depth of 0.2 similar to 0.5. The reduction of the pitch and the flow rate, together with the increase of the transverse angle, can strengthen the secondary flow in spiral concentrators.

关键词： Spiral concentrator flow field velocity distribution design parameters

来源：评论

学校读者我要写书评

暂无评论

Minimum cost-based design of isolated PV-wind hybrid system considering the PV tilt angle and wind turbine hub height as design parameters using genetic algorithm

引用

INTERNATIONAL JOURNAL OF ENERGY RESEARCH 2021年第9期45卷 13149-13162页

作者： Ibrahim, Khaled Hosny Mohamed Ahmed, Eslam Saleh, Saber Mohamed Fayoum Univ Fac Engn Elect Engn Dept Al Fayyum Egypt Fayoum Univ Fac Engn Math & Phys Engn Dept Al Fayyum Egypt

The optimal sizing of a hybrid energy system may be a difficult undertaking problem because of the huge number of structure settings and the irregular nature of solar radiation and wind power sources. This issue has a place with the classification of combinatorial enhancement, and its solution dependent on the classical technique may be a waste of time. In the present paper, the generation cost of isolated PV-wind by bird system is minimized by increasing the capacity factor of the system by adjusting both of PV-tilt angle and wind turbine hub height such that the average generated power is as near as possible to the generation peak. By considering the PV-tilt angle and the turbine hub height, the diversity between the two generation patterns increases resulting in lower cost. The objective of the present paper is to find the optimal design of the PV-wind hybrid system based on minimum cost criterion using a genetic algorithm. Also, it studies the effect of considering the PV-tilt angle and wind turbine hub height as design parameters for different diversity levels of wind speed and sun irradiance patterns.

关键词： constraints cost design parameters fitness genes PV tilt angle reliability wind turbine hub

来源：评论

学校读者我要写书评

暂无评论

Methodology developed for the definition of the design parameters and associated safety criteria of the Filtered Containment Venting Systems for Belgian NPPs

引用

ANNALS OF NUCLEAR ENERGY 2016年 93卷 58-64页

作者： Dejardin, Ph. Helman, T. Bulle, J. Dienstbier, J. Oury, L. Sallus, L. Tractebel Engn SA ENGIE Brussels BE Belgium

Following the post-Fukushima stress tests performed in Belgium, Filtered Containment Venting Systems (FCVS) are foreseen to be installed on Belgian Nuclear Power Plants (NPPs) as ultimate means to cope with slow pressurizations of the containments that could occur during potential Severe Accidents (SA). The present paper discusses the methodology supporting the definition of the FCVS main design parameters and associated safety criteria. This methodology, developed by Tractebel Engineering and accepted by the Belgian nuclear Safety Authorities, followed a series of subsequent steps starting with the definition of the safety referential applicable to the FCVS and leading to the identification of a reference sequence, namely the Complete Station BlackOut (CSBO). Then, key parameters for the FCVS design were defined (e.g. pressure range, venting flow, stored decay heat, stored mass, Decontamination Factors (DF)) along with the associated safety criteria. Several of them were assessed through a well-defined set of supporting calculations. This set included both best estimate representative cases as well as conservative bounding cases performed with state-of-the-art SA codes. The SA codes used were first of all the MELCOR 1.8.6 code and, subsequently, the ASTEC V2.0 code (CPA/IODE modules), considering a chaining methodology. The aim of this approach was to take advantage of the iodine chemistry models features in the CPA/LODE modules of ASTEC to calculate the iodine speciation in the containment and in the FCVS, without having to run a full scope ASTEC calculation. In conclusion, appropriate values for the safety criteria of each design parameters were assessed. In particular, the ones related to the minimum DF relied on a marginal gain approach to cope with the large uncertainties existing when performing dedicated radiological evaluations. Finally, the next steps of this continuous safety assessment of the FCVS that are foreseen to be installed on Belgian NPPs are hig

关键词： Severe accident Filtered Containment Venting System design parameters

来源：评论

学校读者我要写书评

暂无评论

Effect of design parameters and operational conditions on the motion accuracy of hydrostatic thrust bearing

引用

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2020年第8期234卷 1481-1491页

作者： Zha, Jun Chen, Yaolong Zhang, Penghai Chen, Runlin Xi An Jiao Tong Univ Sch Mech Engn West Xianning West Rd 28 Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Shenzhen Res Sch Shenzhen Peoples R China Chongqing Univ Coll Mech Engn Chongqing Peoples R China Xian Univ Technol Sch Mech & Precis Instrument Engn Xian Shaanxi Peoples R China

In this study, the effect of design parameters and operational conditions on motion accuracy of the closed configuration hydrostatic thrust bearing was researched. Key design parameters include land width, nominal oil film thickness, and perpendicularity error between mandrel and thrust plates. Oil supply pressure, external load, and rotation load are the considered operational conditions. Predictions of the induced effect are made by introducing oil film clearance function, governing equations, flow rate continuity equations, and dynamic equations of mandrel to model axial rotation error and angular motion error. The results show that the axial rotation accuracy increased, as land width (larger than 8 mm), nominal oil film thickness, and oil supply pressure increased, but there was little impact on angular motion error. The axial rotation error and angular motion error increased with the increase in the external load and rotation speed. Confirmation of the perpendicularity error has been achieved, in this study, by conducting experiments, using ultra-precision measuring machine. In addition, axial rotation error was tested on a hydrostatic rotary table and compared with the simulation results to check the validity of the proposed method. The results provide useful design guidelines and operation advice for hydrostatic thrust bearing in high-precision machine tools.

关键词： Hydrostatic thrust bearing design parameters operational conditions motion accuracy

来源：评论

学校读者我要写书评

暂无评论

An AUV stability estimation method by considering rudder design parameters

引用

OCEAN ENGINEERING 2024年第Part1期313卷

作者： Mei, Yuan Gao, Jiaxin Lin, Jianjie Song, Xiaowen Zhejiang Univ Sch Mech Engn State Key Lab Fluid Power & Mechatron Syst Hangzhou 310058 Peoples R China Zhejiang Univ Sch Mech Engn Zhejiang Key Lab Adv Mfg Technol Hangzhou 310058 Peoples R China

Stability is a critical characteristic of Autonomous Underwater Vehicles (AUVs). During the initial design stage, selecting an appropriate rudder design is essential to ensure the overall stability performance of the AUV. This study introduces a method for predicting the stability of AUVs equipped with different rudder configurations. By parametric modeling based on the geometric characteristics of X-rudders, the rudder area, aspect ratio, and position parameters, which significantly impact AUV stability, were selected as the primary research objects. Formulas were derived to estimate the associated hydrodynamic forces and moments critical for assessing the stability index. Validation of this approach is conducted through comparison with Computational Fluid Dynamics (CFD) simulations. The results show that this method effectively predicts the hydrodynamic behavior of AUVs, facilitating stability assessments across various rudder designs.

关键词： Control surfaces AUV stability Hydrodynamic derivatives design parameters Computational fluid dynamics

来源：评论

学校读者我要写书评

暂无评论

Effects of design parameters on the Multiphysics Performance of High-Speed Permanent Magnet Machines

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2020年第5期67卷 3472-3483页

作者： Du, Guanghui Xu, Wei Zhu, Jianguo Huang, Na Huazhong Univ Sci & Technol Sch Elect & Elect Engn State Key Lab Adv Electromagnet Engn & Technol Wuhan 430074 Peoples R China Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia CRRC Yongji Elect Co Ltd Xian 710016 Peoples R China

In the design of high-speed permanent magnet machines (HSPMMs), comprehensive effects of design parameters on the various properties of electromagnetic loss, rotor stress, rotor critical speed, and temperature distribution must be analyzed to obtain the optimal design. The aim of this paper is to examine the effects of design parameters, such as the pole number, stator slots number, number of conductors per slot, permanent magnet (PM) thickness, PM pole arc coefficient, air gap length, rotor diameter, core length, and sleeve thickness, on multiphysics performance based on a high-power HSPMM. A reasonable design is determined according to the abovementioned analysis that satisfies all specified multiphysics constraints. The theoretical results are confirmed by the experimental results on a prototype in terms of electromagnetic, mechanical, and thermal characteristics such as back electromotive force, no-load loss, full-load current, overspeed experiment, and temperature distribution.

关键词： Rotors Stator cores Stator windings Stress Windings design parameters high-speed permanent magnet machine (HSPMM) multiphysics rotor stress rotordynamics temperature

来源：评论

学校读者我要写书评

暂无评论

The Effects of design parameters on Performance and NO Emissions of Steam-Injected Diesel Engine with Exhaust Gas Recirculation

引用

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2014年第5期39卷 4119-4129页

作者： Kokkulunk, Gorkem Gonca, Guven Parlak, Adnan Yildiz Tech Univ Marine Engn Dept Istanbul Turkey Yildiz Tech Univ Naval Architecture & Marine Engn Dept Istanbul Turkey

In this study, an engine test with steam injection and EGR is conducted for investigating the effects of engine design parameters such as compression ratio (CR), charge temperature and pressure and equivalent ratio on a direct injection diesel engine performance and NO emissions using zero-dimensional single-zone combustion model. After the results obtained from the model are validated and well suited with those experimental studies of the diesel engines running with 20% steam ratio and 10% EGR, some important design parameters are investigated by using the theoretical model. As results, it was shown that effective efficiency, effective power and NO emissions increase with the increase of CR, inlet pressure for a constant equivalence ratio and inlet temperature. However, effective power and efficiency increase to certain values and then reduce, while NO emissions constantly decrease as the inlet pressure increases for various equivalence ratios.

关键词： Compression ratio design parameters Steam injection EGR NO emission Single-zone combustion model

来源：评论

学校读者我要写书评

暂无评论

A low carbon process design method of sand casting based on process design parameters

引用

JOURNAL OF CLEANER PRODUCTION 2018年第Part1期197卷 1408-1422页

作者： Zheng, Jun Huang, Binbin Zhou, Xingjian Zhejiang Univ Sci & Technol Sch Mech & Automot Engn Hangzhou Zhejiang Peoples R China

The widespread use of sand casting technology has brought tremendous pressure on the environment due to its energy consumption, waste discharge, and process related carbon emissions. A plan should begin at the design phase of the casting, in order to achieve low carbon sand castings or sand castings with low greenhouse gas emissions. Accurate prediction of carbon emission in sand casting is the basis for carbon emission reduction. To calculate and reduce carbon emission of sand castings during the sand casting process design phase, a low carbon process design method of sand casting based on process design parameters is proposed. The process design of sand casting includes various parameters. Three types of sand casting carbon source model were built by three categories of process design parameters analysis of sand mold casting. so as to predict the carbon emission of sand mold casting. The feasibility of the proposed method to estimating the carbon emission in the process design stage was validated by using a practical example. Through the comparison of the two process design schemes based on this method, it can be proved that carbon emissions have decreased significantly. Moreover, we can know the amount of carbon emissions from each type of carbon source can be predicted. A low carbon sand casting process during the sand casting process design phase can be created by this method. The optimization of process design parameters was useful to the reduce carbon emissions of the sand casting and benefited to achieve the aim of reach sustainable manufacturing. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： design parameters Carbon emissions calculation Low carbon Sand casting

来源：评论

学校读者我要写书评

暂无评论

Estimation of design parameters for Braced Excavation: Numerical Study

引用

INTERNATIONAL JOURNAL OF GEOMECHANICS 2013年第3期13卷 234-247页

作者： Chowdhury, Subha Sankar Deb, Kousik Sengupta, Aniruddha Indian Inst Technol Dept Civil Engn Kharagpur 721302 W Bengal India

This paper discusses the development of a numerical model for a braced excavation to estimate the various design parameters that significantly influence the excavation's behavior. The results of the numerical model were compared with those of a reported case study of a braced excavation in sand, and close agreement between the results was observed. The developed model is used for parametric study to show the influence of different design parameters, such as strut stiffness, wall thickness, strut arrangement and the embedded depth of the wall on strut force, maximum moment developed in the wall, maximum lateral displacement of the wall, and maximum vertical displacement of ground surface. It was found that, among all the combinations studied, a particular type of strut arrangement for a particular ratio of embedded depth and excavation depth produces the best possible result. A design guideline is also presented based on the results of this numerical study. (C) 2013 American Society of Civil Engineers.

关键词： Braced excavation FLAC Stiffness Displacement Embedded depth design parameters Strut force Wall thickness Wall bending moment

来源：评论

学校读者我要写书评

暂无评论

Numerical study of effect of operating and design parameters for design of steam reforming reactor

引用

ENERGY 2013年 61卷 410-418页

作者： Hong, Sung Kook Dong, Sang Keun Han, Jeong Ok Lee, Joong Seong Lee, Young Chul Korea Inst Energy Res Dajeon 305343 South Korea Korea Gas Corp Ansan 426790 South Korea

A numerical study on the design of a steam reforming reactor consisting of several reforming tubes and one burner is conducted with respect to various operating and design parameters such as GHSV (gas hourly space velocity), input heat capacity, catalyst layer length, and number of tubes. The calculation of the reforming reaction rate is coupled with a three-dimensional heat and mass transfer calculation. It is shown that a large temperature gradient exists in the reforming reactor, resulting in significant variation of the gas temperature and reaction rate along the reforming tube. The reduction of the catalyst layer length induces a decrease in H-2 (hydrogen) concentration as well as pressure loss. An increased number of tubes leads to better system efficiency owing to the enhanced heat transfer to the reforming tube. Consequently, to improve the system efficiency and reduce the pressure loss, an increase in heat transfer area and decrease in catalyst layer length should be essential design considerations. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Steam reforming Reactor Numerical study Gas hourly space velocity Input heat capacity design parameters

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：