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China Foundry 2024年第4期21卷 379-386页

作者： Yang Liao Ye-yuan Hu Kosuke Ikeda Ryoji Okabe Rui-fen Wu Ryota Ozaki Qing-yan Xu Key Laboratory for Advanced Materials Processing Technology School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Composite Laboratory Research&Innovation Center Mitsubishi heavy industries Ltd.Nagasaki 8510392Japan

Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during ***,the crystallization behavior of polypropylene shows a strong dependence on cooling rate due to its semi-crystalline ***,the influence of cooling rate on the quality of final product cannot be *** this study,the fast differential scanning calorimetry(FSC)test was performed to study the influence of cooling rate on the non-isothermal crystallization behavior and non-isothermal crystallization kinetics of a copolymer polypropylene(PP BC03B).The results show that the crystallization temperatures and crystallinity decrease as the cooling rate *** addition,two exothermic peaks occur when cooling rate ranges from 30 to 300 K·s^(-1),indicating the formation of another crystal ***,Ozawa and Mo equations were used to explore the non-isothermal crystallization kinetics,and it can be concluded that the Mo method is suitable for this study.

关键词： cooling rate crystallization temperature crystallinity non-isothermal crystallization kinetics FSC copolymer polypropylene

The prediction of projectile-target intersection for moving tank based on adaptive robust constraint-following control and interval uncertainty analysis

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Defence Technology（防务技术） 2024年第1期31卷 351-363页

作者： Cong Li Xiuye Wang Yuze Ma Fengjie Xu Guolai Yang The School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing290014PR China Inner Mongolia North heavy industries Co. Ltd.Baotou014033PR China Nanjing Chenguang Group Co. Ltd.Nanjing210006PR China

To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is *** method proposed provides a novel way to predict the impact point of projectile for moving ***,bidirectional stability constraints and stability constraint-following error are constructed using the Udwadia-Kalaba theory,and an adaptive robust constraint-following controller is designed considering ***,the exterior ballistic ordinary differential equation with uncertainties is integrated into the controller,and the pointing control of stability system is extended to the impact-point control of ***,based on the interval uncertainty analysis method combining Chebyshev polynomial expansion and affine arithmetic,a prediction method of projectile-target intersection is ***,the co-simulation experiment is performed by establishing the multi-body system dynamic model of tank and mathematical model of control *** results demonstrate that the prediction method of projectile-target intersection based on uncertainty analysis can effectively decrease the uncertainties of system,improve the prediction accuracy,and increase the hit *** adaptive robust constraint-following control can effectively restrain the uncertainties caused by road excitation and model error.

关键词： Tank stability control Constraint-following Adaptive robust control Uncertainty analysis Prediction of projectile-target intersection

Effect of solute Ce,Mn,and Si on mechanical properties of silicon steel:insights from DFT calculations

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Journal of Iron and Steel Research International 2024年第3期31卷 700-709页

作者： Xiang-jun Liu Ji-chun Yang Hui-ping Ren Xiao-bin Jia Ming-yi Zhang Chang-qiao Yang School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resource Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina Inner Mongolia North heavy industries Group Co. Ltd.Baotou 014010Inner MongoliaChina Inner Mongolia Metal Material Research Institute Baotou 014010Inner MongoliaChina

The influence of solute Ce,Mn,and Si on the mechanical properties of silicon steel was investigated by first-principles ***,Mn,and Si can all be solubilized in Fe *** significantly reduces the incompressibility and rigidity of the system but also significantly improves the toughness and *** effect of Mn on mechanical properties of the system is not *** has a significant effect on the improvement in incompressibility and rigidity but a limited effect on the improvement in toughness and *** metallic bond strength of Fe-Ce,Fe-Mn,and Fe-Si doped systems is weaker than that of the pure Fe system,which can be used to explain the reduction in the incompressibility and rigidity of these doped *** relatively high electron cloud density in the doped system may be responsible for the increase in toughness.

关键词： Silicon steel Rare earth First-principles calculation Elastic modulus Electronic structure

Effects of PWHT on Microstructure and Mechanical Properties of Weld Metals of Ni-Based Superalloy 617 and 263 for Hyper-Supercritical Power Plants

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Acta Metallurgica Sinica(English Letters) 2016年第12期29卷 1107-1118页

作者： Jeong Kil Kim Hae Ji Park Deog Nam Shim Doosan heavy industries and Construction ChangwonGeongnam Korea

It is well known that solid solution-strengthened alloy 617 and γ′ precipitation-strengthened alloy 263 have excellent mechanical properties and corrosion resistance at high temperatures. Hyper-supercritical power plants work at temperatures above 700 ℃, and these superalloys are considered candidate materials for steam turbines components of these power plants. In this study, gas tungsten arc weldability of these superalloys was evaluated, and the effects of post- weld heat treatment （PWHT） on the microstructural characteristics and the mechanical properties of their weld metals were investigated. Scanning transmission electron microscopy, energy-dispersive spectroscopy and electron probe microanalysis were utilized for the investigation. The experimental results confirmed that these weld metals had different characteristics in microstructure and mechanical properties. PWHT resulted in the precipitation of intergranular carbides, γ′ particles and an increase in tensile strength of these superalloy weld metals. Furthermore, fine γ′ particles, which were not detected in the as-welded metal of alloy 263, were precipitated after PWHT and those particles were the reason for the drastic increase in tensile strength.

关键词： Superalloy Welding Precipitation Segregation

Research on Wet Steam Spontaneous Condensing Flows Considering Phase Transition and Slip

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Journal of Thermal Science 2013年第4期22卷 320-326页

作者： Ke CUI Huan-long CHEN Yan-ping SONG Hiroharu OYAMA School of Energy Science and Engineering Harbin Institute of Technology Mitsubishi heavy industries LTD

A new dual-fluid model considering phase ansition and velocity slip was proposed in this paper and the Cunningham correction was used in the droplet resistance calculation. This dual-fluid model was applied to the numerical simulations of wet steam flow in a 2D LAVAL nozzle and in the White cascade respectively. The results of two simulations demonstrate that the model is reliable. Meanwhile, the spontaneous condensing flow in White cascade was analyzed and it infers that the irreversible loss caused by condensation accounts for the largest share （about 8.78% of inlet total pressure） in total pressure loss while the loss caused by velocity slip takes the smallest share （nearly 0.42%）, and another part of total pressure loss caused by pneumatic factors contributes a less share than condensation, i.e. almost 3.95% of inlet total pressure.

关键词： dual-fluid model wet steam spontaneous condensing flow LAVAL nozzle White cascade.

Surge Control of a Centrifugal Compression System by Using a Bouncing Ball

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Journal of Thermal Science 2008年第2期17卷 141-146页

作者： Yuichiro Asaga Shimpei Mizuki Hoshio Tsujita Shinsuke Ohta Department of Mechanical Engineering Faculty of EngineeringHosei University Mitsubishi heavy industries Ltd.

The purpose of this study is to suppress the fluctuations of surge by a simple passive control method. A bouncing ball system with different weight of the balls was tested. As a result, the bouncing ball system suppressed mild surge without the deterioration of the performance characteristics, and moved the initiation point of surge toward the lower flow rate when the steel ball of 15mm outer diameter was used. The present system was effective to suppress the surge and to widen the stable operating range of a centrifugal compressor when the ball was chosen appropriately.

关键词： centrifugal compressor surge passive control bouncing ball

The simulation of gas production from oceanic gas hydrate reservoir by the combination of ocean surface warm water flooding with depressurization

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Acta Mechanica Sinica 2012年第5期28卷 1287-1295页

作者： Hao Yang Yu-Hu Bai Qing-Ping Li Xinxing heavy industries Corporation Limited China National Offshore Oil Corporation Research Institute

A new method is proposed to produce gas from oceanic gas hydrate reservoir by combining the ocean surface warm water flooding with depressurization which can efficiently utilize the synthetic effects of thermal, salt and depressurization on gas hydrate dissociation. The method has the advantage of high efficiency, low cost and enhanced safety. Based on the proposed conceptual method, the physical and mathematical models are established, in which the effects of the flow of multiphase fluid, the kinetic process of hydrate dissociation, the endothermic process of hydrate dissociation, ice-water phase equilibrium, salt inhibition, dispersion, convection and conduction on the hydrate disso- ciation and gas and water production are considered. The gas and water rates, formation pressure for the combination method are compared with that of the single depressurization, which is referred to the method in which only depres- surization is used. The results show that the combination method can remedy the deficiency of individual producing methods. It has the advantage of longer stable period of high gas rate than the single depressurization. It can also reduce the geologic hazard caused by the formation defor- mation due to the maintaining of the formation pressure by injected ocean warm water.

关键词： Gas hydrate reservoir Ocean surface warmwater flooding Depressurization Numerical simulation Combination exploitation

Improvements of model-test method for cavitation-induced pressure fluctuation in marine propeller

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Journal of Hydrodynamics 2013年第4期25卷 599-605页

作者： LEE Jeung-Hoon HAN Jae-Moon PARK Hyung-Gil SEO Jong-Soo Samsung Ship Model Basin (SSMB) Marine Research Institute Samsung Heavy Industries Science Town

Although the prediction of propeller cavitation-induced pressure fluctuation strongly depends on the model-scalemeasure- ment in a cavitation tunnel, there is still a lack of correlation with full-scale data. This paper deals with the enhancement of such a correlation deficiency by improving the conventional model-test technique, two majors of which are in the following. One is to take into account the boundary layer effect of wooden fairing plate at the ceiling of water cavitation tunnel. The other is to avoid the reso- nance frequency range of model-ship via adjusting the revolution speed of model propeller. Through a case study, for which both model and full-scale test data are available, the improved method in this study shows its validness, and furthermore a close correla- tion with full scale measurement.

关键词： cavitation boundary layer resonance

Conjugate calculation of a film-cooled blade for improvement of the leading edge cooling configuration

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Propulsion and Power Research 2013年第1期2卷 1-9页

作者： Norbert Moritz Karsten Kusterer Dieter Bohn Takao Sugimoto Ryozo Tanaka Tomoki Taniguchi B&B-AGEMA GmbH Juelicher Str.338Aachen 52070Germany RWTH Aachen Aachen 52056Germany kawvasaki heavy industries LTD.Gas Turbine&Machinery CompanyAkashi 673-8666Japan

Great efforts are still put into the design process of advanced film-cooling *** particular,the vanes and blades of turbine front stages have to be cooled extensively for a safe *** conjugate calculation technique is used for the three dimensional thermal load prediction of a fim-cooled test blade of a modern gas ***,it becomes possible to take into account the interaction of internal flows,external flow,and heat transfer without the prescription of heat transfer *** focus of the investigation is laid on the leading edge part of the *** numerical model consists of all internal flow passages and cooling hole rows at the leading ***,the radial gap flow is also part of the *** comparison with thermal pyrometer measurements shows that with respect to regions with high thermal load a qualitatively and quantitatively good agreement of the conjugate results and the measurements can be *** particular,the region in the vicinity of the mid-span section is exposed to a higher thermal load,which requires further improvement of the cooling *** the achieved results demonstrate that the conjugate calculation technique is applicable for reasonable prediction of three-dimensional thermal load of complex cooling configurations for blades.

关键词： Gas turbine Rotor blade Film-cooling Conjugate heat transfer Conjugate calculation Pyrometer measurement

DEVELOPMENT OF THE RISK-BASED MAINTENANCE OPTIMIZATION SYSTEM FOR FOSSIL POWER PLANTS

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 381-386页

作者： D.Watanabe Y.Chuman N.Nishimura H.Matsumoto K.Tominaga F.Sakata T.Kuroishi Nagasaki R&D Center Mitsubishi Heavy Industries Ltd. Fukahori-Machi Nagasaki 851-0392 Japan Nagasaki Shipyard & Machinery Works Mitsubishi Heavy Industries Ltd. Akunoura-Machi Nagasaki 850-8610 Japan Power Systems Headquarters Mitsubishi Heavy Industries Ltd. Minato-Ku Tokyo 108-8215 Japan

Cost reduction in electric power generation is a major management concern, and it is therefore necessary to reduce maintenance expenses while upholding plant reliability. A maintenance optimization system 'FREEDOM', which uses RBM technique, DCF (discounted cash flow) and NPV (net present value) calculation functions, has been newly developed. This system probabilistically evaluates the lifetime of boiler and turbine and quantitatively calculates the risk defined as the cumulative probability of failure multiplied by the consequence of failure. Economically optimized timing of inspection and alternative countermeasure such as repair and replacement are then recommended. This system has already been applied to seven plants in Japan, and its effectiveness has been confirmed.

关键词： plant asset management risk based maintenance probabilistic life assessment maintenance optimization