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Effect of duct Geometry on Shock Wave discharge

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Journal of thermal Science 2006年第4期15卷 349-354页

作者： Y.-H.Kweon Y.Miyazato t.Aoki H.-d.Kim t.Setoguchi department of Energy and Environmental Engineering Kyushu UniversityKasuga 816-8580Japan Faculty of Environmental Engineering The University of KitakyushuKitakyushu 808-0135Japan School of Mechanical Engineering Andong National UniversityAndong 760-749Korea department of Mechanical System Engineering Saga UniversitySaga 840-8502Japan

this paper describes computational work to understand the unsteady flow-field of a shock wave discharging from an exit of a duct and impinging upon a flat plate. A flat plate is located downstream, and normal to the axis of the duct. the distance between the exit of the duct and flat plate is changed. In the present study, two different duct geometries （i.e., square and cross section） are simulated to investigate the effect of duct geometry on the un-steady flows of a shock wave. In computation, the total variation diminishing （tVd） scheme is employed to solve three-dimensional, unsteady, compressible, Euler equations. Computations are performed over the range of shock Mach number from 1.05 to 1.75. Computational results can predict the three-dimensional dynamic behaviour of the shock wave impinging upon the flat plate. the results obtained show that the pressure increase generated on the plate by the shock impingement depends on the duct geometry and the distance between the duct exit and plate, as well as the shock Mach number. It is also found that for the duct with cross-section, the unsteady loads acting on the flat plate are less, compared with the square duct.

关键词： unsteady flow compressible flow shock wave shock impingement duct geometry

Proton Emission–Recent Results and Future Prospects

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原子核物理评论 2016年第2期33卷 180-183页

作者： R.d.Page d.t.Joss department of Physics Oliver Lodge LaboratoryUniversity of Liverpool

Considerable progress has been made in the study of proton-emitting nuclei since the first observation of direct proton emission nearly half a century ago. this has led to improvements in our understanding of this rare decay process and provided invaluable nuclear structure data far from the valley of beta stability. this paper reviews the implications of some recent results for exotic iridium, rhenium and tantalum isotopes and considers prospects for future experimental studies of proton-emitting nuclei located at and above the N = 82 neutron shell closure.

关键词： proton emission alpha decay reduced proton-decay width

A New Measurement of ^11Be(p,d) transfer Reaction

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Chinese Physics Letters 2018年第8期35卷 14-18页

作者： Ying Jiang Jian-Ling Lou Yan-Lin Ye dan-Yang Pang Jie Chen Zhi-Huan Li Yu-Cheng Ge Qi-te Li Jing Li Wei Jiang Ye-Lei Sun Hong-Liang Zang Yun Zhang Wei Liu Gen Li N.Aoi E.Ideguchi H.J.Ong J.Lee Jin Wu Hong-Na Liu Chao Wen Y.Ayyad K.Hatanaka d.t.tran t.Yamamoto M.tanaka t.Suzuki t.t.Nguyen School of Physics and State Key Laboratory of Nuclear Physics and technology Peking University Beijing 100871 School of Physics and Nuclear Energy Engineering Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang University Beijing 100191 Research Centre for Nuclear Physics Osaka university Osaka 567-0047 Japan Institute of Physical and Chemical Research Saitama 351-0198 Japan

A new ^11Be（p,d） transfer reaction experiment is performed in inverse kinematics with a radioactive11 Be beam at26.9 MeV. three low-lying states, namely the 0＋ground state, the 2^＋ state at Ex = 3.37 MeV, and the multiplet at around 6 MeV in10 Be, are populated by this one-neutron transfer reaction. these three states in10 Be are clearly discriminated from the -value spectrum, which is rebuilt from energies and angles of the recoil deuterons in coincidence with10 Be. A spectroscopic factor for each state is extracted by comparing the experimental differential cross sections to the theoretical calculation results using the finite range adiabatic distorted wave approximation method with different global nucleon-nucleus potentials. It is found that the newly extracted spectroscopic factors for the 0＋and 2＋states are consistent with the previous ones, but the factor for the multiplet is smaller than the value in the reference, and the possible reason is discussed.

关键词： Be A New Measurement of p,d

FINItE ELEMENt ANALYSIS FOR MICROStRUCtURE EVOLUtION IN HOt FINISHING ROLLING OF StEEL StRIPS

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Acta Metallurgica Sinica(English Letters) 2007年第2期20卷 79-86页

作者： Z.d. Qu S.H. Zhang d.Z. Li Z.t. Wang Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China College of Material Science and Engineering Taiyuan University of Science andTechnology Taiyuan 030024 China Shenyang Ligong University Shenyang 110168 China

A computer model that describes the evolution of microstructures during the hot finishing rolling of SS400 steel has been proposed. It has been found that the microstructure strongly depends on processing of materials and on their parameters, which affected the history of the thermomechanical variables, such as temperature, strain, and strain rate. to investigate the microstructural evolutions during the hot finishing rolling process, the rigid-thermoviscoplastic finite element method （FEM） has been combined with dynamic recrystallization, static recrystallization, and grain growth models. the simulation results show a good agreement with those from the prediction software online.

关键词： finite element method (FEM) finishing rolling microstructure evolution recrystallization

REdUCtION BEHAVIOR OF IRON ORE PELLEtS CONtAININGCARBON UNdER NON-ISOtHERMAL CONdItION

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Acta Metallurgica Sinica(English Letters) 2000年第5期13卷 1059-1067页

作者： X.M.Yang Y.S.Xie d.G.Wang d.B.Huang t.J.Yang L.t.Kong Institute of Chemical Metallurgy The Chinese Academy of Sciences Beijing 100080China University of Science and technology Beijing Beijing 100083China

the reduction behavior of iron ore pellets containing carbon under non-isothermal condition in the temperature range from 573 to 1373 K was investigated in a laboratory scale setup. the test results show that carbon content has no obvious effect on reduction degree of composite pellets (C/O mole ratio=1.0) by CO in the temperature range from 573 to 1373 K under linear temperature-rising program; reduction degree of iron ore pellets containing carbon is large in 90%CO-10%CO2 mixture than that of in 100%CO atmosphere or in 80%CO-20%CO2 mixture; the s type temperature-rising program has a better effect than that of linear one in increasing the reduction degree; and reduction degree of slower linear temperature-rising program is greater than that of faster one, but the final reduction degrees, i.e., those at the highest temperature are about the same for various CO partial pressures or temperature-rising programs. the kinetic analysis also shows that the reduction of iron ore-carbon composite pellets by CO or CO-CO2 mixture under non-isothermal condition should be controlled by surface reaction, and the apparent reduction activation energy changes with the reduction progress under various test conditions.

关键词： iron ore pellet containing carbon reduction behavior kinetics activation energy non-isothermal

Finite element simulations on the mechanical properties of MHS materials

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Acta Mechanica Sinica 2007年第1期23卷 65-75页

作者： Z. Y. Gao t. X. Yu d. Karagiozova department of Mechanical Engineering Hong Kong University of Science &Technology Clear Water Bay Kowloon Hong Kong China Institute of Mechanics Bulgarian Academy of Sciences Acad. G. Bonchev Street Block 4 Sofia 1113 Bulgaria

Finite element simulations are carried out to examine the mechanical behavior of the metallic hollow sphere （MHS） material during their large plastic deformation and to estimate the energy absorbing capacity of these materials under uniaxial compression. A simplified model is proposed from experimental observations to describe the connection between the neighboring spheres, which greatly improves the computation efficiency. the effects of the governing physical and geometrical parameters are evaluated; whilst a special attention is paid to the plateau stress, which is directly related to the energy absorbing capacity. Finally, the empirical functions of the relative material density are proposed for the elastic modulus, yield strength and plateau stress for FCC packing arrangement of hollow spheres, showing a good agreement with the experimental results obtained in our previous study.

关键词： Cellular material Hollow sphere Large plastic deformation Numerical simulation FEM

IMPROVEMENt OF MECHANICAL PROPERtIES OF MARtENSItIC StAINLESS StEEL BY PLASMA NItRIdING At LOW tEMPERAtURE

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 21-29页

作者： Y. t. Xi d.X. Liu d. Han Z.F. Han Corrosion and Protection Research Lab Northwestern Polytechnical University Xi＇an 710072 China Xi＇an Shaangu Power Co. Ltd Xi＇an 710611 China

A series of experiments were carried out to study the influence of low temperature plasma nitriding on the mechanical properties of AISI 420 martensitic stainless steel. Plasma nitriding experiments were carried out for 15 h at 350℃ by means of dC- pulsed plasma in 25%N2＋ 75%H2 atmosphere. the microstructure, phase composition, and residual stresses profiles of the nitrided layers were determined by optical microscopy and X-ray diffraction. the microhardness profiles of the nitridied surfaces were also studied. the fatigue life, sliding wear, and erosion wear loss of the untreated specimens and plasma nitriding specimens were determined on the basis of a rotating bending fatigue tester, a ball-on-disc wear tester, and a solid particle erosion tester. the results show that the 350℃ nitrided surface is dominated by c-Fe3N and ON, which is supersaturated nitrogen solid solution. they have high hardness and chemical stabilities. So the low temperature plasma nitriding not only increases the surface hardness values but also improves the wear and erosion resistance. In addition, the fatigue limit of AISI 420 steel can also be improved by plasma nitriding at 350℃ because plasma nitriding produces residual compressive stress inside the modified layer.

关键词： Martensitic stainless steel Plasma nitriding Low temperature Mechanical properties

Optimization Study of a Coanda Ejector

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Journal of thermal Science 2006年第4期15卷 331-336页

作者： H.d.Kim G.Rajesh t.Setoguchi S.Matsuo School of Mechanical Engineering Andong National University388Songcheon-dongAndongGyeongbuk 760-749Korea department of Mechanical Engineering Saga University1HonjoSaga 840-8502Japan

the Coanda effect has long been employed in the aerospace applications to improve the performances of various devices. this effect is the ability of a flow to follow a curved contour without separation and has well been utilized in ejectors where a high speed jet of fluid emerges from a nozzle in the ejector body, follows a curved surface and drags the secondary flow into the ejector. In Coanda ejectors, the secondary flow is dragged in the ejector due to the primary flow momentum. the transfer of momentum from the primary flow to the secondary flow takes place through turbulent mixing and viscous effects. the secondary flow is then dragged by turbulent shear force of the ejector while being mixed with the primary flow by the persistence of a large turbulent intensity throughout the ejector. the performance of a Coanda ejector is studied mainly based on how well it drags the secondary flow and the amount of mixing between the two flows at the ejector exit. the aim of the present study is to investigate the influence of various geometric parameters and pressure ratios on the Coanda ejector performance. the effect of various factors, such as, the pressure ratio, primary nozzle and ejector configurations on the system performance has been evaluated based on a performance parameter defined elsewhere. the performance of the Coanda ejector strongly depends on the primary nozzle configuration and the pressure ratio. the mixing layer growth plays a major role in optimizing the performance of the Coanda ejector as it decides the ratio of secondary mass flow rate to primary mass flow rate and the mixing length.

关键词： Coanda ejector compressible mixing layer flow dragging mixing length induced flow

StUdY ON tHE tEXtURE OF A FRICtION StIR WELdEd Mg-Al-Ca ALLOY

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 335-340页

作者： d. t. Zhang M. Suzuki K. Maruyama Graduate School of Environmental Studies Tohoku University 6-6-02 Aoba-yamaAoba-ku Sendai 980-8579 Japan College of Mechanical Engineering South China University of TechnologyGuangzhou 510640 China

Macro-texture of an Mg-Al-Ca alloy prepared by friction stir welding （FSW） was investigated through pole figure measurement and X-ray diffraction （XRd） pattern analysis. It was found that at the top and bottom surfaces of friction stir zone （FSZ）, （0002） basal planes of magnesium tend to be arranged parallel to the plate surface. In the cross section of FSZ, no obvious texture had evolved and （0002） basal planes showed a random distribution.

关键词： friction stir welding (FSW) Mg-Al-Ca alloy texture microstructure