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boundary conditions for Limited Area Models Based on the Shallow Water Equations

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Communications in Computational Physics 2013年第8期14卷 664-702页

作者： Arthur Bousquet Madalina Petcu Ming-Cheng Shiue Roger Temam Joseph Tribbia The Institute for Scientific Computing and Applied Mathematics Indiana UniversityBloomingtonIN 47405USA Laboratoire de Mathematiques et Applications UMR 6086Universite de PoitiersFrance The Institute of Mathematics of the Romanian Academy BucharestRomania Department of Applied Mathematics National Chiao Tung UniversityHsinchuTaiwan National Center for Atmospheric Research BoulderColoradoUSA.

A new set of boundary conditions has been derived by rigorousmethods for the shallow water equations in a limited *** aim of this article is to present these boundary conditions and to report on numerical simulations which have been performed using these boundary *** new boundary conditions which are mildly dissipative let the waves move freely inside and outside the *** problems considered include a one-dimensional shallow water system with two layers of fluids and a two-dimensional inviscid shallow water system in a rectangle.

关键词： boundary conditions finite volumes shallow water

boundary conditions of the dynamicnumerical model for the Chinese mainland lithosphere

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Acta Seismologica Sinica(English Edition) 1999年第2期12卷 148-154页

作者：张东宁许忠淮 Institute of Geophysics China Seismological Bureau Beijing China

The numerical dynamic model of Chinese mainland lithosphere's stress and strain field was constructed withelasto-viscous creep constitive relation. The most recent data of the stress field of Chinese mainland and thehorizontal movement velocity of the crust blocks were used as constraint conditions. The values of the boundalsforce were computed by trial-and-error method. The effect of the Qinghai-Xizang Plateau's excess potential energyto the movement of Chinese mainland was studied also in this model. The results of the numerical computing showthat, recent rapid raising of the Qinghai-Xizang Plateau and the generation of normal faults in the southem part ofthe plateau resulted from the convergence of Indian Plate to the Eurasian Plate, and also from the rapid convectivethinning of the lower lithosphere. Horizontal extension of the Qinghai-Xizang Plateau is the main dynamic factorto torm the present tectonic framework of the Chinese mainland. The compressive loads on the eastern boundaryof the model were mainly applied by the subduction of the Pacific Plate. The compression from the PhilippinePlate maybe slight.

关键词： Chinese mainland stress field movement rate boundary conditions finite element

Application of inverse method to estimation of boundary conditions during investment casting simulation

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Acta Metallurgica Sinica(English Letters) 2009年第6期22卷 429-434页

作者： Haipeng JIN Jiarong LI Dong PAN National Key Laboratory of Advanced High Temperature Structural Materials Institute of AeronauticalMaterials Beijing 100095 China Key Lab for Advanced Materials Processing Technology MOE Department of Mechanical EngineeringTsinghua University Beijing 100084 China

Inverse method was used in single crystal superalloy DD6 processing simulation during solidification. Numerical modeling coupled with experiments has been used to estimate the interface heat transfer coefficient （IHTC） between the surface of slab casting and inner mold. Calculated temperature dependent values of IHTC were obtained from a numerical solution. The calculated temperatures agreed well with the measurement of cooling profile.

关键词： Numerical simulation Single crystal Inverse method boundary conditions

Frequency Analysis of Multiple Layered Cylindrical Shells under Lateral Pressure with Asymmetric boundary conditions

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 23-31页

作者： ISVANDZIBAEI Mohammad Reza JAMALUDDIN Hishamuddin RAJA HAMZAH Raja Ishak Faculty of Mechanical Engineering Universiti Teknologi Malaysia

Natural frequency characteristics of a thin-walled multiple layered cylindrical shell under lateral pressure are studied. The multiple layered cylindrical shell configuration is formed by three layers of isotropic material where the inner and outer layers are stainless steel and the middle layer is aluminum. The multiple layered shell equations with lateral pressure are established based on Love＇s shell theory. The governing equations of motion with lateral pressure are employed by using energy functional and applying the Ritz method. The boundary conditions represented by end conditions of the multiple layered cylindrical shell are simply supported-clamped（SS-C）, free-clamped（F-C） and simply supported-free（SS-F）. The influence of different lateral pressures, different thickness to radius ratios, different length to radius ratios and effect of the asymmetric boundary conditions on natural frequency characteristics are studied. It is shown that the lateral pressure has effect on the natural frequency of multiple layered cylindrical shell and causes the natural frequency to increase. The natural frequency of the developed multilayered cylindrical shell is validated by comparing with those in the literature. The proposed research provides an effective approach for vibration analysis shell structures subjected to lateral pressure with an energy method.

关键词： multiple layered ritz method lateral pressure shell boundary conditions

Evaluating the different boundary conditions to simulate airflow and heat transfer in Double-Skin Facade

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Building Simulation 2022年第5期15卷 799-815页

作者： Javad Ahmadi Mohammadjavad Mahdavinejad Olena Kalyanova Larsen Chen Zhang Afsaneh Zarkesh Somayeh Asadi Highperformance Architecture Laboratory Department of ArchitectureTarbiat Modares UniversityJalal-e Al Ahmad HighwayNasr bridgeTehranIran Department of Built Environment Faculty of Engineering and ScienceDivision of Architectural EngineeringAalborg UniversityAalborgDenmark Department of Architectural Engineering Pennsylvania State UniversityPA 16801USA

The CFD simulation accuracy mostly depends on the appropriate setting of boundary conditions and numerical simulation *** study shows the influence of two types of boundary condition settings on the CFD simulation results of Double-Skin Facade(DSF)for a specific *** two boundary settings are the constant temperature on the DSF surfaces called boundary A,and boundary B is defined via solar radiation using the Discrete Ordinate radiation Model(DOM).The paper verified both the numerical simulations using the experimental *** the numerical results of two types of boundaries with experimental data shows that both cases underestimated the values lower than 5.2 K and 0.1 m/s for the temperature and velocity respectively at the regarded measured *** A gives more accurate temperature prediction results,while boundary B shows velocity magnitude closer to the measurements in the middle height of the cavity;the average temperature and velocity differences between the two boundary types are 0.6 K and 0.003 m/s respectively which are ***,the selection of boundary conditions depends on study purposes,however,when the DSF is equipped with blinds and if there is not enough data in hand but the exact value of solar irradiation,using the boundary B approach is suggested;it can provide reasonable results associated with multi-type of thermal boundary conditions at the same ***,if the goal is to investigate the flow pattern in the DSF,boundary B is argued to perform better than the constant temperature boundary condition.

关键词： Double-Skin Facade boundary conditions thermal performance airflow irradiation

ON THE L_∞ CONVERGENCE AND THE EXTRAPOLATION METHOD OF A DIFFERENCE SCHEME FOR NONLOCAL PARABOLIC EQUATION WITH NATURAL boundary conditions

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Journal of Computational Mathematics 2001年第5期19卷 449-458页

作者： Wan, Z.-S. Sun, Z.-Z. Institute of Applied Physics and CM P.O. Box 8009 Beijing 100088 China

In paper (J. Comput. Appl. Math., 76 (1996), 137-146), a difference scheme for a class of nonlocal parabolic equations with natural boundary conditions was derived by the method of reduction of order and the unique solvability and second order convergence in L2-norm are proved. In this paper, we prove that the scheme is second order convergent in L∞ norm and then obtain fourth order accuracy approximation in L∞ norm by extrapolation method. At last, one numerical example is presented.

关键词： Approximation theory boundary conditions Convergence of numerical methods Extrapolation

Enhanced Phase Change Heat Storage of Layered Backfill Body under Different boundary conditions

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Journal of Thermal Science 2023年第3期32卷 1190-1212页

作者： ZHANG Xiaoyan ZHAO Min LIU Lang ZHAO Yujiao HUAN Chao ZHANG Bo Energy School Xi'an University of Science and TechnologyXi'an 710054China Key Laboratory of Western Mines and Hazards Prevention Ministry of Education of ChinaXi'an 710054China

In view of the high temperature problem faced by mining activities,the coordinated mining of ore deposit and geothermal energy is a solution in line with the concept of green *** layered backfill body with finned double-pipe heat exchanger continuously exchanges heat with the surrounding thermal environment,which plays an effective role in gathering geothermal *** this paper,the heat storage process of each layered backfill body under different boundary conditions is simulated by *** results show the heat storage characteristic of layered backfill body can be significantly improved by adding fins to the double-pipe heat *** the whole,the heat storage effect of bottom layer backfill body(BLBB)is the *** total heat storage capacity of top layer backfill body(TLBB),middle layer backfill body(MLBB)and BLBB with the finned double-pipe heat exchanger is 666.3 kJ,662.2 kJ,1003.0 kJ;1639.0 kJ,1760.8 kJ,1911.2 kJ and 1731.1 kJ,1953.3 kJ,1962.8 kJ respectively at 1 h,8 h and 24 *** study explores the law of heat storage of layered backfill body under different boundary conditions and also expands the idea for layered backfill body to efficiently accumulate geothermal energy.

关键词： layered backfill body boundary conditions phase change heat storage finned double-pipe exchanger geothermal energy of mine

Discussion on electromagnetic crack face boundary conditions for the fracture mechanics of magneto-electro-elastic materials

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Acta Mechanica Sinica 2006年第3期22卷 233-242页

作者： Baolin Wang Jiecai Han Center for Composite Materials Harbin Institute of Technology Harbin 150001 China

This paper discusses electromagnetic boundary conditions on crack faces in magneto- electroelastic materials, where piezoelectric, piezomagnetic and magnetoelectric effects are coupled. A notch of finite thickness in these materials is also addressed. Four idealized electromagnetic boundary conditions assumed for the crack-faces are separately investigated, i.e. （a） electrically and magnetically impermeable （crack-face）, （b） electrically impermeable and magnetically permeable, （c） electrically permeable and magnetically impermeable, and （d） electrically and magnetically permeable. The influence of the notch thickness on important parameters, such as the field intensity factors, the energy release rate at the notch tips and the electromagnetic fields inside the notch, are studied and the results are obtained in closed-form. Results under different idealized electromagnetic boundary conditions on the crack-face are compared, and the applicability of these idealized assumptions is discussed.

关键词： Fracture mechanics Magnetoelectroelastic materials boundary conditions Notch Crack

On the initial values of kinematic and dynamic free-surface boundary conditions for water wave problems

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Journal of Hydrodynamics 2020年第5期32卷 1024-1027页

作者： Dong-qiang Lu Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

The kinematic and dynamic boundary conditions on the free surface of a fluid should be posed for water wave *** the framework of potential theory for an inviscid and incompressible fluid with an irrotational motion,the combined boundary condition,which involves the velocity potential only,is often used by eliminating the elevation terms *** a combination is correct for the solutions in the frequency domain,and is not feasible for an initial-boundary-value problem in the time domain since it leads to a totally different physical *** correct initial conditions for pure gravity waves and hydroelastic waves are presented.

关键词： Initial values boundary conditions water wave hydroelasticity