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Precision forging technology for aluminum alloy

Lei DENG, Xinyun WANG, Junsong JIN, Juchen XIA

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 25-36 doi: 10.1007/s11465-018-0477-y

摘要：

Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, automobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and good corrosion resistance. However, during forging processes, underfilling, folding, broken streamline, crack, coarse grain, and other macro- or microdefects are easily generated because of the deformation characteristics of aluminum alloys, including narrow forgeable temperature region, fast heat dissipation to dies, strong adhesion, high strain rate sensitivity, and large flow resistance. Thus, it is seriously restricted for the forged part to obtain precision shape and enhanced property. In this paper, progresses in precision forging technologies of aluminum alloy parts were reviewed. Several advanced precision forging technologies have been developed, including closed die forging, isothermal die forging, local loading forging, metal flow forging with relief cavity, auxiliary force or vibration loading, casting-forging hybrid forming, and stamping-forging hybrid forming. High-precision aluminum alloy parts can be realized by controlling the forging processes and parameters or combining precision forging technologies with other forming technologies. The development of these technologies is beneficial to promote the application of aluminum alloys in manufacturing of lightweight parts.

关键词： precision forging     aluminum alloy     closed die forging     flow control forging     hybrid-forming technology    

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近β锻造推翻陈旧理论发展了三态组织

周义刚,曾卫东,俞汉清

《中国工程科学》 2001年 第3卷 第5期   页码 61-66

摘要：

将坯料置于相变的临界点附近10～15℃加热、锻造、锻后水冷，随后，不是采用时效处理，而是先进行高温韧化再低温强化处理。近β锻造的组织不再是等轴α量过多，或是为零的网篮条状α的结构模式；而是约含20%等轴α、50%～60%条状α构成的网篮和β转变基体组成的三态组织。这种结构不仅丰富和发展了国 际上钛合金已有的4种组织类塑（等轴、双态、网篮和并列），而且将等轴和网篮组织的性能优势集于一身，由此带来的力学性能超过了国内外相关技术的性能水平：能在不降低塑性，不丧失热稳定性的条件下，提高材料的高温性能、低周疲劳性能和断裂韧性，在改善性能的同时提高使用温度。近β锻造适用于（α+β)型合金， 还可应用于α、近α和近β型合金，其研究成果已用于制造了多种发动机盘件、飞机和导弹等重要结构件。

关键词： 钛合金     近β锻造     三态组织    

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Impact of selection of DC base values and DC link control strategies on sequential AC-DC power-flow convergence

Shagufta KHAN,Suman BHOWMICK

《能源前沿（英文）》 2015年 第9卷 第4期   页码 399-412 doi: 10.1007/s11708-015-0374-6

摘要： This paper demonstrates the convergence of the integrated AC-DC power-flow algorithm as affected by the selection of different base values for the DC quantities and adoption of different control strategies for the DC link. For power-flow modeling of integrated AC-DC systems, the base values of the various DC quantities can be defined in several ways, giving rise to different sets of per-unit system equations. It is observed that different per-unit system models affect the convergence of the power-flow algorithm differently. In a similar manner, the control strategy adopted for the DC link also affects the power-flow convergence. The sequential method is used to solve the DC variables in the Newton Raphson (NR) power flow model, where AC and DC systems are solved separately and are coupled by injecting an equivalent amount of real and reactive power at the terminal AC buses. Now, for a majority of the possible control strategies, the equivalent real and reactive power injections at the concerned buses can be computed a-priori and are independent of the NR iterative loop. However, for a few of the control strategies, the equivalent reactive power injections cannot be computed a-priori and need to be computed in every NR iteration. This affects the performance of the iterative process. Two different per-unit system models and six typical control strategies are taken into consideration. This is validated by numerous case studies conducted on the IEEE 118-bus and 300-bus test systems.

关键词： AC-DC power-flow     Newton-Raphson method     high voltage direct current (HVDC) control strategy    

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Red soil for sediment capping to control the internal nutrient release under flow conditions

Lei Xia, Guo Liu, Chunmei Chen, Meiyan Wen, Yangyang Gao

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0886-2

摘要： The inhibition of sediment nitrogen (N) and phosphorus (P) release seems necessary. Red soil (RS) was firstly used as sediment capping material under flow conditions. RS capping can effectively reduce the N and P release from sediment. Nitrogen (N) and phosphorus (P) released from the sediment to the surface water is a major source of water quality impairment. Therefore, inhibiting sediment nutrient release seems necessary. In this study, red soil (RS) was employed to control the nutrients released from a black-odorous river sediment under flow conditions. The N and P that were released were effectively controlled by RS capping. Continuous-flow incubations showed that the reduction efficiencies of total N (TN), ammonium (NH -N), total P (TP) and soluble reactive P (SRP) of the overlying water by RS capping were 77%, 63%, 77% and 92%, respectively, and nitrification and denitrification occurred concurrently in the RS system. An increase in the water velocity coincided with a decrease in the nutrient release rate as a result of intensive water aeration.

关键词： Sediment     Red soil capping     Flow conditions     Nitrogen     Phosphorus    

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Numerical study and control method of interaction of nucleation and boundary layer separation in condensingflow

Liansuo AN , Zhi WANG , Zhonghe HAN ,

《能源前沿（英文）》 2009年 第3卷 第3期   页码 254-261 doi: 10.1007/s11708-009-0047-4

摘要： The spontaneous nucleation flow in turbine cascade was numerically studied. The model was implemented within a full Navier–Stokes viscous flow solution procedure and the process of condensation was calculated by the quadrature method of moments that shows good accuracy with very broad size distributions. Results were presented for viscous and inviscous flow, showing the influence of boundary layer separation and wake vortices on spontaneous nucleation. The results show that the degree of flow separation in wet steam flow is greater than that in superheated steam flow due to condensation shock and that the loss cannot be neglected. Furthermore, the impact of boundary layer separation and wake vortices on velocity profiles and its implications for profile loss were considered. The calculations showed that layer separation and wake vortices influence nucleation rate, leading to different droplet distributions. A method for controlling homogeneous nucleation and for reducing degree of flow separation in high-speed transonic wet steam flow was presented. The liquid phase parameter distribution is sensitive to the suction side profile of turbine cascade, which impacts the nucleation rate distribution leading to different droplet distributions and affects the degree of flow separation. The numerical study provides a practical design method for turbine blade to reduce wetness losses.

关键词： wet steam     two-phase flow     spontaneous condensation     numerical simulation     flow separation     profile loss    

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Mechanism and control factors of hydrate plugging in multiphase liquid-rich pipeline flow systems: a

Shuwei ZHANG, Liyan SHANG, Zhen PAN, Li ZHOU, You GUO

《能源前沿（英文）》 2022年 第16卷 第5期   页码 747-773 doi: 10.1007/s11708-022-0830-z

摘要： There is nothing illogical in the concept that hydrates are easily formed in oil and gas pipelines owing to the low-temperature and high-pressure environment, although requiring the cooperation of flow rate, water content, gas-liquid ratio, and other specific factors. Therefore, hydrate plugging is a major concern for the hydrate slurry pipeline transportation technology. In order to further examine potential mechanisms underlying these processes, the present paper listed and analyzed the significant research efforts specializing in the mechanisms of hydrate blockages in the liquid-rich system, including oil-based, water-based, and partially dispersed systems (PD systems), in gathering and transportation pipelines. In addition, it summarized the influences of fluid flow and water content on the risk of hydrate blockage and discussed. In general, flow rate was implicated in the regulation of blockage risk through its characteristic to affect sedimentation tendencies and flow patterns. Increasing water content can potentiate the growth of hydrates and change the oil-water dispersion degree, which causes a transition from completely dispersed systems to PD systems with a higher risk of clogging. Reasons of diversity of hydrate plugging mechanism in oil-based system ought to be studied in-depth by combining the discrepancy of water content and the microscopic characteristics of hydrate particles. At present, it is increasingly necessary to expand the application of the hydrate blockage formation prediction model in order to ensure that hydrate slurry mixed transportation technology can be more maturely applied to the natural gas industry transportation field.

关键词： hydrate     flow rate     water content     mechanism of pipeline blockage     rich liquid phase system    

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Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

《环境科学与工程前沿（英文）》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1222-4

摘要： A model-free sewer-WWTP integrated control was proposed. A dynamic discrete control based on the water level was developed. The approach could improve the sewer operation against flow fluctuation. The approach could increase transport capacity and enhance pump efficiency. This study aims to propose a multi-point integrated real-time control method based on discrete dynamic water level variations, which can be realized only based on the programmable logic controller (PLC) system without using a complex mathematical model. A discretized water level control model was developed to conduct the real-time control based on data-automation. It combines the upstream pumping stations and the downstream influent pumping systems of wastewater treatment plant (WWTP). The discretized water level control method can regulate dynamic wastewater pumping flow of pumps following the dynamic water level variation in the sewer system. This control method has been successfully applied in practical integrated operations of sewer-WWTP following the sensitive flow disturbances of the sewer system. The operational results showed that the control method could provide a more stabilized regulate pumping flow for treatment process; it can also reduce the occurrence risk of combined sewer overflow (CSO) during heavy rainfall events by increasing transport capacity of pumping station and influent flow in WWTP, which takes full advantage of storage space in the sewer system.

关键词： Sewer system     Integrated control     Discrete control     Water level    

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Operation and control of flow manufacturing based on constraints management for high-mix/low-volume production

GUAN Zailin, PENG Yunfang, MA Li, ZHANG Chaoyong, LI Peigen

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 454-461 doi: 10.1007/s11465-008-0083-5

摘要： The existing technology of flow manufacturing, which is mainly appropriate for high volume and repetitive production, is proven difficult to be applied in high-mix/low-volume environments. To adapt lean production into the latter, a new type of flow manufacturing is proposed based on flow path management technology. This paper first describes the general operation framework of the proposed new mode. The main idea is the dynamic formation of adaptable virtual production lines (called flow paths) corresponding to different product families. The application of different theories of constraints/drum-buffer-rope (TOC/DBR) control policies depends on the differences in scope of variety and scale of demand for these product families. The overall architecture of the proposed mechanism of constraint management-based operation and control is introduced. For the implementation, a mathematical programming method is suggested for the dynamic planning of flow paths, and a TOC/DBR ‘path-specific’ mechanism with group scheduling is used for the control over each flow path. We also study other critical issues including the identification and management of resource bottlenecks, and the setting of the buffer size in the deployment of the TOC/DBR mechanism.

关键词： appropriate     management technology     scheduling     technology     different    

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Substance flow analysis for an urban drainage system of a representative hypothetical city in China

Hua BAI, Siyu ZENG, Xin DONG, Jining CHEN

《环境科学与工程前沿（英文）》 2013年 第7卷 第5期   页码 746-755 doi: 10.1007/s11783-013-0551-y

摘要： This paper discusses the use of substance flow analysis (SFA) as a tool to support quantified research on urban drainage systems. Based on the principle of mass balance, a static substance flow model is established to describe and examine the routes and intensities of water, chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) for a representative hypothetical city (RH city) in China, which is a devised and scaled city using statistical characteristics of urban circumstances at the national level. It is estimated that the annual flux of water, COD, TN and TP through the urban drainage system in 2010 was 55.1 million m , 16037.3 t, 1649.5 t and 209.7 t, respectively. The effluent of wastewater treatment plant (WWTP) was identified as the most important pathway for pollutant emissions, which contributed approximately 60% of COD, 65% of TN and 50% of TP to receiving water. During the wastewater treatment process, 1.0 million m , 7042.5 t, 584.2 t and 161.4 t of the four studied substances had been transmitted into sludge, meanwhile 3813.0 t of COD and 394.0 t of TN were converted and emitted to the atmosphere. Compared with the representative hypothetical city of 2000, urban population and the area of urban built districts had expanded by approximately 90% and 80% respectively during the decade, resulting in a more than threefold increase in the input of substances into the urban drainage system. Thanks to the development of urban drainage systems, the total loads of the city were maintained at a similar level.

关键词： substance flow analysis (SFA)     urban drainage system     representative hypothetical city (RH city)     water pollution control    

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Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membranefouling control

《环境科学与工程前沿（英文）》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1531-x

摘要：

• Ceramic membrane filtration showed high performance for surface water treatment.

关键词： Ceramic membrane     Coagulation     Polytitanium chloride     Membrane fouling    

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Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

《能源前沿（英文）》 2011年 第5卷 第4期   页码 386-397 doi: 10.1007/s11708-011-0156-8

摘要： By performing gas flow field numerical simulations for several inlet Reynolds numbers (from 2 × 10 to 9 × 10 ) and byflow ratios (from 10% to 20%), the present study has proposed to improve the flow passage of an inlet particle separator. An adjacent objective of the study is to lower pressure losses of the inlet particle separator (IPS). No particle has been included in the gas flow for a -epsilon turbulence model. The velocity distribution in different sections and the pressure coefficient along the duct have been analyzed, which indicates that there exist important low-velocity regions and vortices in the separation area. Therefore, the profile of streamlines along the original passage has been considered. This profile illustrated a vacuum region in the same area. All investigations suggest that the separation area is the most critical one for fulfilling the objective on pressure losses limitation. Then the flow passage improvement method has focused on the separation area. An improved shape has been designed in order to suit smoothly to the streamlines in this region. Similar numerical studies as those for the original shape have been conducted on this improved shape, confirming some considerable enhancements compared with the original shape. The significant vortices which appear in the original shape reduce in amount and size. Besides, pressure losses are greatly decreased in both outlets (up to 30% for high Reynolds number) and the flow is uniform at the main outlet. Subsequent engineering surveys could rely on expressions obtained for in both outlets which extend the pressure losses for a wide range of inlet Reynolds numbers. As a result, the numerical calculations demonstrate that the flow passage improvement method applied in this study has succeeded in designing a shape which enhances the flow behavior.

关键词： streamlines     pressure losses     flow passage improvement     inlet particle separator (IPS)    

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流体内磁驱动微米机器人运动前沿研究综述 Review Article

苗佳淼1,2,王潇朴2,周燕2,叶敏2,赵洪宇2,许若愚1,钱辉环1,2

《信息与电子工程前沿（英文）》 2023年 第24卷 第11期   页码 1520-1540 doi: 10.1631/FITEE.2300054

摘要： 磁驱动微米机器人能够在人体内局部低侵入性地执行特定任务。为到达体内病灶区域，微米机器人常常需要在比静止液体更为复杂的流动血液内进行导航运动。因此，相应的精准控制方案设计更具挑战性。目前已有许多关于磁控微米机器人在流体内的运动控制及其理论研究。本文回顾总结了有关磁控微米机器人在流体中的最新研究进展，包括流动系统的建立、运动的动力学建模以及控制方法。此外，讨论了当前面临的挑战和局限性。希望本文为微米机器人在复杂流体环境中的高效控制提供新的思路，并加快微米机器人在临床应用中的研究。

关键词： 微米机器人；流体；动力学建模；控制    

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物质流分析的跟踪观察法

陆钟武

《中国工程科学》 2006年 第8卷 第1期   页码 18-25

摘要：

流动，是物质（如铜、铝等）流动和流体流动二者所具有的基本特征，基于这个论点，简要地回顾了流体力学中研究流体流动的两种方法，即拉格朗日法和欧拉法；相应地提出了物质流分析的两种方法，即跟踪观察法和定点观察法。由于前者在文献中未见报道，因此对它进行了重点说明。强调了物质流的跟踪观察法既适用于稳态物质流（产品产量不变），也适用于非稳态物质流（产品产量增长或下降）。以钢铁产品生命周期的铁流图为例，说明了物质流的跟踪模型。在引入了物质流的非稳度后，提出了物质流各项指标的计算式，以及它们之间的相互关系。以瑞典铅酸电池系统为对象，计算了其中铅流的各项指标，并进行了必要的分析。

关键词： 物质流的研究方法     物质流的跟踪观察法     物质流的基本公式     物质流的非稳度    

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UPFC setting to avoid active power flow loop considering wind power uncertainty

Shenghu LI, Ting WANG

《能源前沿（英文）》 2023年 第17卷 第1期   页码 165-175 doi: 10.1007/s11708-020-0686-z

摘要： The active power loop flow (APLF) may be caused by impropriate network configuration, impropriate parameter settings, and/or stochastic bus powers. The power flow controllers, e.g., the unified power flow controller (UPFC), may be the reason and the solution to the loop flows. In this paper, the critical existence condition of the APLF is newly integrated into the simultaneous power flow model for the system and UPFC. Compared with the existing method of alternatively solving the simultaneous power flow and sensitivity-based approaching to the critical existing condition, the integrated power flow needs less iterations and calculation time. Besides, with wind power fluctuation, the interval power flow (IPF) is introduced into the integrated power flow, and solved with the affine Krawcyzk iteration to make sure that the range of active power setting of the UPFC not yielding the APLF. Compared with Monte Carlo simulation, the IPF has the similar accuracy but less time.

关键词： active power loop flow (APLF)     unified power flow controller (UPFC)     wind power uncertainty     interval power flow (IPF)    

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A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

《环境科学与工程前沿（英文）》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1800-y

摘要：

● A spindle-shaped influent chamber was designed and equipped in FCDI system.

关键词： Spindle-shaped chamber     Desalination performance     Flow electrode capacitive deionization    

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标题 作者 时间 类型 操作

Precision forging technology for aluminum alloy

Lei DENG, Xinyun WANG, Junsong JIN, Juchen XIA

期刊论文

近β锻造推翻陈旧理论发展了三态组织

周义刚,曾卫东,俞汉清

期刊论文

Impact of selection of DC base values and DC link control strategies on sequential AC-DC power-flow convergence

Shagufta KHAN,Suman BHOWMICK

期刊论文

Red soil for sediment capping to control the internal nutrient release under flow conditions

Lei Xia, Guo Liu, Chunmei Chen, Meiyan Wen, Yangyang Gao

期刊论文

Numerical study and control method of interaction of nucleation and boundary layer separation in condensingflow

Liansuo AN , Zhi WANG , Zhonghe HAN ,

期刊论文

Mechanism and control factors of hydrate plugging in multiphase liquid-rich pipeline flow systems: a

Shuwei ZHANG, Liyan SHANG, Zhen PAN, Li ZHOU, You GUO

期刊论文

Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

期刊论文

Operation and control of flow manufacturing based on constraints management for high-mix/low-volume production

GUAN Zailin, PENG Yunfang, MA Li, ZHANG Chaoyong, LI Peigen

期刊论文

Substance flow analysis for an urban drainage system of a representative hypothetical city in China

Hua BAI, Siyu ZENG, Xin DONG, Jining CHEN

期刊论文

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membranefouling control

期刊论文

Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

期刊论文

流体内磁驱动微米机器人运动前沿研究综述

苗佳淼1,2,王潇朴2,周燕2,叶敏2,赵洪宇2,许若愚1,钱辉环1,2

期刊论文

物质流分析的跟踪观察法

陆钟武

期刊论文

UPFC setting to avoid active power flow loop considering wind power uncertainty

Shenghu LI, Ting WANG

期刊论文

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

期刊论文