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Temperature correction for Thickness Measurements of Hot Rolled steel Plates

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Journal of Iron and steel Research International 2010年第12期17卷 23-29页

作者： c Gheorghies s condurache-Bota Faculty of sciences Dunarea de Jos University

Measuring the thickness of steel plates during the hot rolling process Is crucial tor getnng me necessary feedback to obtain the desired values at room temperature. The dilatation and the phase transformations of steel occur during heating and subsequent cooling and rolling strongly influences the results of thickness measurements. The radiometrie method provides the necessary means for making real-time and fully automatized measurements of steel thickness during rolling, if only the temperature correction is precisely known and taken into consideration. This article proves that the experimental results concerning the relative variation of steel thickness and corresponding massthickness variation can be correctly explained by means of the theory of metal dilatation correlated with the theory of nuclear radiation absorption when passing through a metal or metallic alloy, such as steel.

关键词： hot rolling dilatation phase transformation temperature correction attenuation

convergence,scalarization and continuity of Minimal solutions in set Optimization

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Journal of the Operations Research society of china 2024年第3期12卷 773-793页

作者： Karuna c.s.Lalitha Department of Mathematics University of DelhiDelhiDelhi110007India Department of Mathematics University of Delhi South CampusNew DelhiDelhi110021India

The paper deals.w.th the study of two different aspects of stability in the given space as.w.ll as the image space,where the solution concepts are based on a partial order relation on the family of bounded subsets of a real normed linear *** first aspect of stability deals.w.th the topological set convergence of families of solution sets of perturbed problems in the image space and Painlevé–Kuratowski set convergence of solution sets of the perturbed problems in the given *** convergence in the given space is also established in terms of solution sets of scalarized perturbed *** second aspect of stability deals.w.th semicontinuity of the solution set maps of parametric perturbed problems in both the spaces.

关键词： Topological convergence Painlevé-Kuratowski convergence Upper semicontinuity Lower semicontinuity stability scalarization

A 2-D FINITE ELEMENT MODEL sIMULATION OF THE MELTING PROcEss OF Al-Ti ALLOY IN VAcUUM INDUcTION FURNAcE wITH cOLD cRUcIBLE(VIFcc)

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Acta Metallurgica sinica(English Letters) 2004年第3期17卷 229-237页

作者： s.c.chu s.s.Lian F.K.chen Institute of Materials science and Engineering National Taiwan UniversityTaibei(Taipei)Institute of Materials Science and EngineeringNational Taiwan UniversityTaibei(Taipei)Institute of Mechanical EngineeringNational Taiwan UniversityTaibei(Taipei)

The development of a numerical model for the melting process of Al--Ti alloy targetmaterial in vacuum induction furnace with cold crucible (VIFcc)was described. It isa two--dimensional computational methodology to calculate electromagnetic field, heattransfer field and fluid flow field. Based on the aid of the finite element method withthe commercial software--ANsYs, a superimposition method of a layer of copper anda slit to simulate the VIFcc melting process.w.s used. The method was effectiveto save large quantity of memory and computing time. Meanwhile, a temperaturedistribution profile during the melting process.w.s obtained. Validity of the model wasconfirmed by comparison between the result from calculation and those from directmeasurement by optical pyrometer and indirect investigation by ingot macrostructure.A relatively good agreement was found. Further, a nearly directional solidificationstrvcture was obtained under properly controlling the cooling rate and heating power.Therefore, such model developed in this article is feasible.

关键词： VIFcc ANsYs superimposition ingot macrostructure

Experimental study of corner separation and unsteady characteristics in linear compressor cascades.w.th and without sweeping jet actuator

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Propulsion and Power Research 2024年第3期13卷 360-374页

作者： s.w.chen w.H.Li c.Xu Q.H.Meng school of Energy science and Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150001China AVIc shenyang Aircraft Design and Research Institute Shenyang 110035China

sweeping jet actuator(sJA)has been widely applied for activeflow control in *** this paper,the sJA character in compressor cascade and its performance for separation control in innerflows are ***-averaged and transientflowfield measurement,together with visualization methods are *** is found that endwall effects are important for both sJA behaviors and sJA performance for separation control in compressor *** is a maximum of 12.7%total pressure loss reduction with sJA placed near the separation position,close to the endwall and under *** characteristic frequencies in theflowfield contribute to the capture of influence regions of vortices and excitation *** concentrated shedding vortices and sJA jets impact region helped to judge that sJA energizes low momentumfluids in a large region and matches the high loss core *** be concrete,theflow separation control mechanism of sJA lies on the interruption of the blade suction surface boundary layer development and the restriction of the lifting of the boundary layer from end-wall towards blade suction surface.

关键词： compressor cascade Activeflow control sweeping jet actuator corner separation Oilflow visualization

Dual-wavelength Holmium-Doped Fiber Laser Pumped by Thulium-Ytterbium co-Doped Fiber Laser

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chinese Physics Letters 2016年第5期33卷 39-42页

作者： A.A.Latiff A.Dhar s.w.Harun I.M.Babar s.Das M.c.Paul H.Ahmad Photonics Research center University of Malaya Faculty of Electronics & computer Engineering Universiti Teknikal Malaysia Melaka csIR-central Glass and ceramic Research Institute Department of Electrical Engineering University of Malaya

we present an all-fiber dual-wavelength holmium-doped veloped holmium-doped fiber （HDF） as a gain medium fiber laser operating in 2 #m region using a newly de- The proposed fiber laser is constructed by using a hybrid gain medium, i.e., a thulium ytterbium co-doped fiber （TYDF） and an HDF in conjunction with a simple half-opened linear cavity, which is formed by a broadband mirror and an output coupler reflector. without the HDF, the TYDF laser operates at wavelengths of 1991 and 1999nm with a signal-to-noise ratio of more than 34dB and the slope efficiency of 26.16 %. with the HDF, dual-wavelength output lines are obtained at 2075 and 2083nm with signal-to-noise ratios of more than difference between the two peaks of less than 1 dB at 17dB, 3dB bandwidth of less than 0.2nm and the power the TYDF laser pump power of 320row.

关键词： by in is as nm of Dual-wavelength Holmium-Doped Fiber Laser Pumped by Thulium-Ytterbium co-Doped Fiber Laser HDF

A Finite Element Method for Modelling Electromechanical wave Propagation in Anisotropic Piezoelectric Media

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communications in computational Physics 2007年第2期2卷 271-292页

作者： s.Rahman H.P.Langtangen c.H.w.Barnes cavendish Laboratory Cambridge UniversityJ J Thomson AvenueCambridgeCB3 OHEUnited Kingdom simula Research Laboratory Martin Linges v 17Fornebu P.O.Box 1341325 LysakerNorway

we describe and evaluate a numerical solution strategy for simulating surface acoustic waves(s.w.)through semiconductor devices.w.th complex *** multi-physics problem is of particular relevance to the design of s.w.based quantum electronic *** mathematical model consists of two coupled partial differential equations for the elastic wave propagation and the electric field,respectively,in anisotropic piezoelectric *** equations are discretized by the finite element method in space and by a finite difference method in *** latter method yields a convenient numerical decoupling of the governing *** describe how a computer implementation can utilize the decoupling and,via object-oriented programming techniques reuse independent codes for the Poisson equation and the linear time-dependent elasticity *** we apply the simulator to a simplified model problem for verifying the implementation,and thereafter we show that the methodology is capable of simulating a real-world case from nanotechnology,involving s.w. in a geometrically non-trivial device made of Gallium ***:***,***,*** Key words:Finite element method,piezoelectric surface acoustic waves,Gallium Arsenide.

关键词： Finite element method piezoelectric surface acoustic waves Gallium Arsenide.

Mobile augmented reality visualization and collaboration techniques for on-site finite element structural analysis

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International Journal of Modeling, simulation, and scientific computing 2018年第3期9卷 2-21页

作者： w.K.Li A.Y.c.Nee s.K.Ong NUs Graduate school for Integrative sciences and Engineering National University of singapore 28 Medical Drive Singapore 117456Singapore Mechanical Engineering Department National University of singapore 9 Engineering Drive 1 Singapore 117576Singapore∗mpeneeyc@nus.edu.sg

In this paper,a mobile augmented reality(AR)framework for on-site finite element analysis(FEA)is *** proposed framework is achieved using a client–server *** performance of FEA relies on several important components,namely,computational power,visualization technique,and numerical *** renders intuitive computer-generated contents directly on a user’s *** FEA with AR helps users through enhancing their perception and interaction with the engineering *** and effective visualization of these data using an AR platform can reduce the misinterpretation in spatial and logical *** the past decade,AR has undergone a transition from desktop to phablet *** platforms enable user exploration of FEA results in *** client side uses a hybrid method to visualize FEA results in the mobile AR *** addition,a user can collaborate with other users by using the result sharing function.A prototype with basic functions has been built and a case study has been implemented to demonstrate the visualization method and evaluate the overall performance.

关键词： Augmented reality scientific visualization on-site finite element analysis client-server.

A Novel Dynamic Quadrature scheme for solving Boltzmann Equation with Discrete Ordinate and Lattice Boltzmann Methods

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communications in computational Physics 2012年第4期11卷 1397-1414页

作者： c.T.Hsu s.w.chiang K.F.sin Department of Mechanical Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong

The Boltzmann equation(BE)for gas flows is a time-dependent nonlinear differential-integral equation in 6 *** current simplified practice is to linearize the collision integral in BE by the BGK model using Maxwellian equilibrium distribution and to approximate the moment integrals by the discrete ordinatemethod(DOM)using a finite set of velocity quadrature *** simplification reduces the dimensions from 6 to 3,and leads to a set of linearized discrete *** main difficulty of the currently used(conventional)numerical procedures occurs.w.en the mean velocity and the variation of temperature are large that requires an extremely large number of quadrature *** this paper,a novel dynamic scheme that requires only a small number of quadrature points is *** is achieved by a velocity-coordinate transformation consisting of Galilean translation and thermal normalization so that the transformed velocity space is independent of mean velocity and *** enables the efficient implementation of Gaussian-Hermite *** velocity quadrature points in the new velocity space are fixed while the correspondent quadrature points in the physical space change from time to time and from position to *** this dynamic nature in the physical space,this new quadrature scheme is termed as the dynamic quadrature scheme(DQs).The DQs.w.s implemented to the DOM and the lattice Boltzmann method(LBM).These new methods.w.th DQs are therefore termed as the dynamic discrete ordinate method(DDOM)and the dynamic lattice Boltzmann method(DLBM),*** new DDOM and DLBMhave been tested and validated with several testing *** the same accuracy in numerical results,the proposed schemes are much faster than the conventional ***,the new DLBM have effectively removed the incompressible and isothermal restrictions encountered by the conventional LBM.

关键词： Dynamics quadrature dynamic discrete ordinatemethod dynamic lattice Boltzmann method thermal lattice Boltzmann method

Pore size Distribution of High Performance Metakaolin concrete

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Journal of wuhan University of Technology(Materials science) 2002年第1期17卷 42-46页

作者： c.s.Poon s.c.Kou L.Lam Department of civil and structural Engineering The Hong Kong Polytechnic University Hong Kong China

The compressive strength, porosity and pore size distribution of high performance metakaolin (MK) concrete were investigated. concretes containing 0,5% , 10% and 20% metakaolin were prepared at a water / cementitious material ratio ( w/c) of 0. 30. In parallel, concrete mixtures.w.th the replacement of cement by 20% fly ash or 5 and 10% silica fume were prepared for comparison. The specimens.w.re cured in water at 27℃ for 3 to 90 days. The results show that at the early age of curing (3 days and 7 days), metakaolin replacements increase the compressive strength, but silica fume replacement slightly reduces the compressive strength. At the age of and after 28 days , the compressive strength of the concrete with metakaolin and silica fume replacement increases. A strong reduction in the total porosity and average pore diameter were observed in the concrete with MK 20% and 10% in the first 7 days.

关键词： high performance concrete metakaolin pore size distribution