检索结果-内蒙古大学图书馆

Flutter prediction by an Euler method on non-moving Cartesian grids with gridless boundary conditions

COMPUTERS & FLUIDS 2006年第6期35卷 571-586页

作者： Kirshman, DJ Liu, F Univ Calif Irvine Dept Mech & Aerosp Engn Irvine CA 92697 USA

A method is presented for the prediction of transonic flutter by the Euler equations on a stationary Cartesian mesh. Local grid refinement is established through a series of embedded meshes, and a gridless method is implemented for the treatment of surface boundary conditions. For steady flows, the gridless method applies surface boundary conditions using a weighted average of the flow properties within a cloud of nodes in the vicinity of the surface. The weighting is established with shape functions derived using a least-squares fitting of the surrounding nodal cloud. For unsteady calculations, a perturbation of the shape functions is incorporated to account for a fluctuating surface normal direction. The nature of the method provides for efficient and accurate solution of transient flow problems in which surface deflections are small (i.e. flutter calculations) without the need for a deforming mesh. Although small deviations in angle of attack are considered, the mean angle of attack can be large. Results indicate good agreement with available experimental data for unsteady flow, and with computational results addressing flutter of the Isogai wing model obtained using traditional moving mesh algorithms. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： numerical grid generation (numerical analysis) EULERIAN graphs GRAPH theory boundary value problems -- numerical solutions

来源：评论

学校读者我要写书评

暂无评论

BILINEARIZATION APPROACH FOR DIFFUSION problems INVOLVING THE CALCULATION OF DISSIPATIVE FIELDS

引用

numerical HEAT TRANSFER PART B-FUNDAMENTALS 2009年第6期55卷 457-479页

作者： Mathieu-Potvin, Francois Gosselin, Louis Univ Laval Dept Genie Mecan Quebec City PQ GIV 0A6 Canada

A straightforward procedure is developed to determine dissipation fields (e. g., exergy destruction in conduction, pumping power, Joule heating) from the linear boundary conditions applied on their associated linear diffusion problem (e. g., heat conduction, Darcy flow, electrical flow). The mathematical tool proposed in this article takes advantage of the quadratic (nonlinear) behavior that comes with dissipative fields equations. The first objective of this article is to build a mathematical formulation expressing any dissipation field as a combination of fundamental dissipative fields resulting from decomposed boundary conditions, similarly to linear problems where fundamental solutions may be added with the superposition principle. The second objective is to demonstrate the numerical advantage of this formulation when applied to heat transfer and fluid flow optimization problems. Application of the mathematical tool proposed in this article to boundary control problems provided significant computational time reductions.

关键词： HEAT transfer RESEARCH FLUID dynamics THERMAL conductivity HEAT conduction boundary value problems -- numerical solutions PERMEABILITY JOULE-Thomson effect

来源：评论

学校读者我要写书评

暂无评论

Some existence's results for noncoercive "1-Laplacian" operator

引用

ASYMPTOTIC ANALYSIS 2005年第4期43卷 287-322页

作者： Demengel, F Univ Cergy Pontoise F-95302 Cergy Pontoise France

In this paper we study necessary and sufficient conditions on f and the first eigenfunctions for the 1-Laplacian, for equations of the form [GRPHICS] when q =lambda(1), lambda(1) is the first eigenvalue for the 1-Lapl... 详细信息

In this paper we study necessary and sufficient conditions on f and the first eigenfunctions for the 1-Laplacian, for equations of the form [GRPHICS] when q <= N/(N-1) and lambda >=lambda(1), lambda(1) is the first eigenvalue for the 1-Laplacian.

关键词： DIFFERENTIAL equations -- numerical solutions INTEGRAL equations -- numerical solutions LAPLACIAN operator PARTIAL differential equations EIGENFUNCTIONS boundary value problems -- numerical solutions

来源：评论

学校读者我要写书评

暂无评论

On numerical solution of strongly anisotropic diffusion equation on misaligned grids

引用

numerical HEAT TRANSFER PART B-FUNDAMENTALS 2005年第6期47卷 533-554页

作者： Umansky, MV Day, MS Rognlien, TD Lawrence Livermore Natl Lab Livermore CA 94550 USA

problems with extremely high-transport anisotropy often arise in strongly magnetized plasmas. The numerical solution of the highly anisotropic transport equations becomes quite difficult when the computational grid is not aligned with the strong transport direction, since this can cause large numerical errors. Constructing a finite-difference scheme for a strongly anisotropic diffusion equation on a misaligned grid is discussed, and quantitative assessment of the numerical error is made for a set of example problems.

关键词： ANISOTROPY CRYSTALLOGRAPHY MATTER -- Properties numerical grid generation (numerical analysis) boundary value problems -- numerical solutions PARTIAL differential equations -- numerical solutions numerical analysis

来源：评论

学校读者我要写书评

暂无评论

Axisymmetrical boundary-value problems of elasticity theory for finite-length cylinders and cones

引用

DOKLADY PHYSICS 2011年第7期56卷 407-412页

作者： Popov, G. Ya. Mechnikov Natl Univ UA-65082 Odessa Ukraine

The article presents the solution for boundary-value problems of the elasticity theory of finite-length cylinders and cones to satisfy its axisymmetrical deformation. It says that the integral transform is applied to get the exact solution of boundary-value problem for cylinder torsion and torsion deformation of cone. It mentions that the subsequent use of inversion formulas gives the precise solutions for cylinder and the sliding-seal condition must be fulfilled to find the solution for cone.

关键词： boundary value problems -- numerical solutions CYLINDERS (Engines) CONES DEFORMATIONS (Mechanics) INTEGRAL transforms INVERSIONS (Geometry)

来源：评论

学校读者我要写书评

暂无评论

Tests of perturbative DFT total energy estimates implemented in a Gaussian basis

引用

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY 2004年第3期100卷 245-253页

作者： Zhu, WM Trickey, SB Univ Florida Dept Phys Gainesville FL 32611 USA Univ Florida Dept Chem Quantum Theory Project Gainesville FL 32611 USA

We derive and test an approximate expression for the Kohn-Sham eigenfunctions and total energy associated with a given exchange-correlation functional. The expression is closely related to the approximation given by Benoit et al. (Phys Rev Lett 2001, 87, 226401) but differs by removing an overly stringent orthogonality constraint. Tests on the Li, F, Ne, and Cr atoms done in Gaussian basis sets suggest that the approach is promising, particularly as an alternative to conventional self-consistent field or to the Harris scheme (Phys Rev B 1985, 31, 1770). (C) 2004 Wiley Periodicals, Inc.

关键词： EIGENFUNCTIONS boundary value problems -- numerical solutions GAUSSIAN basis sets (Quantum mechanics) FORCE & energy

来源：评论

学校读者我要写书评

暂无评论

Spectrum of the quantum Neumann model

引用

PHYSICS LETTERS A 2005年第4-6期337卷 360-368页

作者： Bellon, M Talon, A Univ Paris 06 LPTHE UMR 7589 F-75252 Paris 05 France

关键词： EIGENFUNCTIONS boundary value problems -- numerical solutions DIFFERENTIAL equations -- numerical solutions INTEGRAL equations -- numerical solutions

来源：评论

学校读者我要写书评

暂无评论

DIFFRACTION BY AN IMPEDANCE STRIP II. SOLVING RIEMANN-HILBERT problems BY OE-EQUATION METHOD

引用

QUARTERLY JOURNAL OF MECHANICS AND APPLIED MATHEMATICS 2015年第3期68卷 341-362页

作者： Shanin, A. V. Korolkov, A. I. Moscow MV Lomonosov State Univ Dept Phys Moscow 119992 Russia

The current article is the second part of a series of two papers dedicated to the two-dimensional problem of diffraction of acoustic waves by a segment bearing impedance boundary conditions. In the first part, some preliminary steps were made, namely, the problem was reduced to two-matrix Riemann-Hilbert problems. Here these problems are solved with the help of a novel method of OE-equations. Each Riemann-Hilbert problem is embedded into a family of similar problems with the same coefficient and growth condition, but with some other cuts. The family is indexed by an artificial parameter. It is proven that the dependence of the solution on this parameter can be described by a simple ordinary differential equation (ODE1). The boundary conditions for this equation are known and the inverse problem of reconstruction of the coefficient of ODE1 from the boundary conditions is formulated. This problem is called the OE-equation. The OE-equation is solved by a simple numerical algorithm.

关键词： RIEMANN-Hilbert problems RESEARCH SOUND wave scattering SOUND waves -- Diffraction boundary value problems -- numerical solutions ORDINARY differential equations

来源：评论

学校读者我要写书评

暂无评论

Meshless Method for Geometry boundary Identification Problem of Heat Conduction

引用

numerical HEAT TRANSFER PART B-FUNDAMENTALS 2009年第2期55卷 135-154页

作者： Tan, J. Y. Zhao, J. M. Liu, L. H. Harbin Inst Technol Sch Energy Sci & Engn Harbin 150001 Peoples R China Harbin Inst Technol Weihai Sch Auto Engn Weihai Peoples R China

A geometry identification problem of two-dimensional heat conduction is solved by using the least-squares collocation meshless method and the conjugate gradient method. In the least-squares collocation meshless approach for solving the direct heat conduction problem, a number of collocation points and auxiliary points are used to discretize the problem domain, and the collocation points are taken to construct the trial function by moving least-squares approximation. Akima cubic interpolation is employed to transform the geometry boundary inverse problem to the discrete boundary point's inverse problem and approximate the unknown boundary in an inverse iterative process. In order to illustrate the performance and verify the new solution method, four typical cases are considered. The numerical results show that the least-squares collocation meshless method combined with the conjugate gradient method is accurate and stable for solving the geometry identification problem of heat conduction.

关键词： THERMAL conductivity measurement boundary value problems -- numerical solutions LEAST squares MESHFREE methods (numerical analysis) CONJUGATE gradient methods INVERSE problems (Differential equations) -- numerical solutions

来源：评论

学校读者我要写书评

暂无评论

Identification of a moving boundary for a heat conduction problem in a multilayer medium

引用

HEAT AND MASS TRANSFER 2010年第7期46卷 779-789页

作者： Li, Y. S. Wei, T. Lanzhou Univ Sch Math & Stat Lanzhou 730000 Peoples R China

In this paper, we give a uniqueness theorem for the moving boundary of a heat problem in a composite medium. Through solving the Cauchy problem of heat equation in each subdomain, we finally find an approximation to the moving boundary for one-dimensional heat conduction problem in a multilayer medium. The numerical scheme is based on the use of the method of fundamental solutions and a discrete Tikhonov regularization technique with the generalized cross-validation choice rule for a regularization parameter. numerical experiments for five examples show that our proposed method is effective and stable.

关键词： HEAT conduction HEAT transfer boundary value problems -- numerical solutions CAUCHY problem -- numerical solutions HEAT equation -- numerical solutions TEMPERATURE measurements HARMONIC functions (Mathematics) APPROXIMATION theory

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：