• 한국항공우주학회지
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• 제32권8호
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• pp.1-11
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• 2004

본 연구에서는 비정렬 격자계에서 가장 많이 쓰이는 근사 해법 중에 하나인 LU 기법의 Navier-Stokse 방정식에 대한 수렴성 및 안정성에 관한 연구를 수행하였다. 적절한 스칼라 모델 방정식을 사용하여 LU 기법이 갖는 고유한 특성에 관한 해석적 논의를 수행하였으며, 이를 Navier-Stokes 방정식으로 확장하여 해석하였다. 그 결과 LU 기법의 강성도는 격자 종횡비가 높아짐에 띠라, 그리고 격자 레이놀즈 수 감소함에 따라 증가하게 된다. 또한 내부반복계산을 통해서 이러한 강성도가 부분적으로 극복될 수 있음을 보였으며, 평판 난류 유동 해석을 통해서 해석 결과를 검증하였다.

• 소음진동
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• 제10권4호
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• pp.610-614
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• 2000

Cellular Automata(CA)s are used as a simple mathematical model to investigate self-organization in statistical mechanics, which are originally introduced by von Neumann and S. Ulam at the end of the 1940s. CAs provide a framework for a large class of discrete models with homogeneous interactions, which are characterized by the following fundamental properties: 1) CAs are dynamical systems in which space and time are discrete. 2) The systems consist of a regular grid of cells. 3) Each cell is characterized by a state taken from a finite set of states and updated synchronously in discrete time steps according to a local, identical interaction rule. 4) The state of a cell is determined by the previous states of a surrounding neighborhood of cells. A cellular automaton has been attracted wide interest in modeling physical phenomena, which are described generally, partial differential equations such as diffusion and wave propagation. This paper describes one and two-dimensional analysis of wave propagation phenomena modeled by CA, where the local interaction rules were derived referring to the Lattice Gas Model reported by Chen et al., and also including finite difference scheme. Modeling processes by using CA are discussed and the simulation results of wave propagation with one wave source are compared with that by finite difference method.