Project/Area Number |
06650072
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Engineering fundamentals
|
Research Institution | School of Engineering, University of Tokyo |
Principal Investigator |
MORI Masatake University of Tokyo, School of Engineering, Professor, 大学院・工学系研究科, 教授 (20010936)
|
Co-Investigator(Kenkyū-buntansha) |
OGATA Hidenori University of Tokyo, School of Engineering, Research Associate, 大学院・工学系研究科, 助手 (50242037)
FURIHATA Daisuke University of Tokyo, School of Engineering, Research Associate, 大学院・工学系研究科, 助手 (80242014)
SUGIHARA Masaaki University of Tokyo, School of Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (80154483)
|
Project Period (FY) |
1994 – 1996
|
Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
|
Keywords | anomalous diffusion / Cahn-Hilliard equation / nonlinear PDE / discrete variation / difference scheme / dissipative system / conservative system / difference and summation / スピノ-ダル分解 / 異常拡散現象 / 安定性条件 / 自由エネルギー / リアプノフ関数 |
Research Abstract |
Suppose that a uniform mixture of two metals is in an unstable nonequilibrium state and that the mixture evolves from the unstable state to a more stable nonuniform configuration consisting of two phases. Such a phenomenon is call an anomalous diffusion problem and time evolution of such a phenomenon is described by a nonlinear partial differential equation called the Cahn-Hilliard equation. The purpose of the present research project is to establish an efficient difference scheme for stable numerical solution of such kind of nonlinear partial differential equations. The idea of the present method is to start from discretization of the energy of the physical system under consideration and to apply a suitable discrete variation. The key point of the present research exists in this discrete variation. When we discretize the energy we defined the difference operators and the summation operators consistently with the differetial operators and the integration operator. Our method can be applied not only to the Cahn-Hilliard equation but also to a wide class of nonlinear partial differential equations, i. e. partial differential equations for energy dissipative system and for energy conservative system. Examples of equations for the dissipative system and the heat equation and the Cahn-Hilliard equation, and the wave equation and the KdV equation are examples of the equations for the conservative system. Our method were applied successfully to numerical solution of these equations. In the case of the Cahn-Hilliard equation we proved mathematically the stability of the scheme and the convergence of the numerical solution to the exact solution of the original equation.
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