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An AUV stability estimation method by considering rudder design parameters

OCEAN ENGINEERING 2024年 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

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

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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

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Detailed three-phase circuit model for power transformers over wide frequency range based on design parameters

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ELECTRIC POWER SYSTEMS RESEARCH 2012年 92卷 115-122页

作者： Garcia-Gracia, M. Villen, M. Cova, M. A. El Halabi, N. Ctr Res Energy Resources & Consumpt CIRCE Zaragoza 50018 Spain AGM Ctr Univ Def Zaragoza 50090 Spain

This paper presents a detailed three-phase transformer model, the elements of which are expressed analytically according to the physical layout and the design construction parameters of the power transformer. These expressions have been calculated theoretically and verified through finite elements simulations. The proposed model allows to obtain the internal voltage distribution through the three-phase transformer in any type of operating condition, particularly when it is simulated in an electromagnetic time domain transient simulation tool, providing an external and internal characterization of the transformer in a frequency band that can appear in a power system (up to 1 MHz). The obtained results have been compared with both lightning and low frequency tests measurements, showing a good agreement. (C) 2012 Elsevier B.V. All rights reserved.

关键词： High frequency Power transformers design parameters Surge voltage Lightning discharge

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Exergy Analysis of Single-Effect Vapor Absorption System Using design parameters

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JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME 2021年第6期143卷 062105页

作者： Ansari, Khursheed Afroz Azhar, Md. Altamush Siddiqui, M. Indian Inst Technol Dept Energy Sci & Engn Mumbai 400076 Maharashtra India Aligarh Muslim Univ Zakir Husain Coll Engn & Technol Dept Mech Engn Aligarh 202002 Uttar Pradesh India Maulana Mukhtar Ahmad Nadvi Tech Campus Dept Mech Engn Malegaon 423203 Maharashtra India

In the present communication, internal irreversibility at each component of a single-effect vapor absorption refrigeration system has been evaluated and presented. The irreversibility is induced owing to the pressure drop in the shell and tube and energy exchange between the working fluids. Each component of the system is considered to be a shell and tube-type energy exchanger with slight modifications depending upon the applications. Each energy exchanger is divided into three control volumes, namely, tube wall, shell, and tube for which both energy and exergy balances are applied to evaluate the exergy destruction rate (EDR). Moreover, the overall EDR in the energy exchanger is then estimated in the form of pumping work and energy exchange duty. This objective function is further simplified in the form of design parameters such as tube diameter, friction coefficient, number of tubes, number of baffles, and overall heat transfer coefficient for the energy exchanger. In addition to this, optimum generator temperature and minimum EDR of each component of the absorption system have been tabulated and presented. Results show that for a single tube, UA value in the system component ranges from 2.99 W/K to 48.9 W/K depending on the operating conditions and design parameters of the system. Also, the number of tube in the system components ranges from 1108 tubes to 24803 tubes and the number of baffles in the respective components ranges from 2 to 7.

关键词： design parameters vapor absorption system exergy analysis solar energy energy conversion systems energy systems analysis renewable energy

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

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JOURNAL OF CLEANER PRODUCTION 2018年 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

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

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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

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

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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

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

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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

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Optimization of PWR design parameters for implementation in SMRs

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ANNALS OF NUCLEAR ENERGY 2016年 94卷 123-128页

作者： Ashiq, Muhammad Ilyas, Muhammad Ahmad, Siraj-ul-Islam Pakistan Inst Engn & Appl Sci Islamabad Pakistan COMSATS Inst Informat Technol Dept Phys Res Modeling & Simulat RIMS Grp Islamabad Pakistan

In an attempt to enhance the core burn up, this paper focuses on optimization of PWR design parameters for implementation in Small Modular Reactors (SMRs). The reactor core has been modeled using reactor physics codes and analyses are carried out by sequential variation in the design parameters (fuel rod pitch, fuel pellet diameter, and cladding thickness). Different combinations of fuel rod pitch, fuel pellet diameter, and clad thickness that resulted in lower power peaking factor and enhanced multiplication factor are analyzed. It is found that the core burn up can be extended up to 35.1 effective full power days (EFPD) using some suitable combinations. Thermal-hydraulic analysis of the selected core configurations has also been performed to ensure the reactor safety. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Optimization design parameters Cycle burnup Reactor physics codes Reactivity SMR

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Effects of the connecting-rod-related design parameters on the piston dynamics and the skirt-liner lubrication

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING 2013年第6期227卷 885-898页

作者： Meng, Xianghui Ning, Lipu Xie, Youbai Wong, Victor W. Shanghai Jiao Tong Univ Sch Mech & Power Engn Shanghai 200240 Peoples R China Shanghai Jiao Tong Univ State Key Lab Mech Syst & Vibrat Shanghai 200240 Peoples R China MIT Sloan Automot Lab Cambridge MA 02139 USA

With the development of high-performance and high-speed engines, the effects that the connecting-rod-related design parameters have on the performance of the piston-liner system have become more important. Based on a new model of the piston dynamics presented by the present authors, the effects of the connecting-rod-related parameters on the side force, the oil-film thickness, the frictional force, and the piston dynamics are investigated. The results show that the changes in the extra transverse force and the piston's secondary motion are the main reasons for the different performances of the system. When the mass and the rotational inertia of the connecting rod are decreased, the extra transverse force is significantly reduced. When the location of the center of mass of the connecting rod is changed, the extra transverse force obviously changes in amplitude and trend. When the length of the connecting rod is increased, the amplitude of the extra transverse force increases during the upper half-stroke near the top dead center and decreases during the bottom half-stroke near the bottom dead center. Because of these changes in the connecting rod, the change in the extra transverse force leads to different behaviors of the side force, the minimum oil-film thickness, and the piston's secondary motion. However, changing the connection position of the connecting rod to the piston gives rise to very different behaviors of the piston's secondary motion, and the change in the piston's secondary motion generates significant differences in the minimum oil-film thickness. This study shows that the connecting-rod-related parameters are significant to the performance of the piston-liner system.

关键词： Connecting rod design parameters piston dynamics mixed lubrication

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