Pattern formation in Rayleigh-Bénard convection: Numerical simulation with a coupled-map-lattice model  

作　　者：WANGLiang ZHANGGuanghua FUSong 

机构地区：[1]DepartmentofEngineeringMechanics,TsinghuaUniversity,Beijing100084,China

出　　处：《Chinese Science Bulletin》2005年第5期399-406,共8页

基　　金：supported by the National Natural Science Foundation of China(Grant No.10232020)

摘　　要：The various patterns formed in Rayleigh-Bé- nard convection under different conditions are numerically simulated with a coupled-map-lattice model. In the case of a lower aspect ratio (L/d=5), the simulations vividly depicted the main features of the transition process from a laminar state to a soft turbulence and then to a hard turbulence. In this case, the cellular structure in a horizontal section is also reproduced. In the case of a larger aspect ratio (L/d=30), the simulations successfully reproduced the spiral-defect chaos and target chaos in the initial stage of the pattern evolution which were recently found in experiments. In this case, for a fluid of Pr=1, it is verified in simulations that both the ideal straight rolls and spiral-defect chaos are stable attractors in the same parameter regime, and that the initial condition is a decisive factor for which one of the two is formed. In the same case, for a fluid of Pr=4, the target patterns are dominant instead of the spirals, the sizes and distributions of the target are also notably dependent on the initial condition.The various patterns formed in Rayleigh-Be-nard convection under differentconditions are numerically simulated with a coupled-map-lattice model. In the case of a lower aspectratio (L/d=S), the simulations vividly depicted the features of the transition process from alaminar state to a soft turbulence and then to a hard turbulence. In this case, the cellularstructure in a horizontal section is also reproduced. In the case of a larger aspect ratio (L/d=3Q),the simulations successfully reproduced the spiral-defect chaos target chaos in the initial of thepattern evolution which were recently found in experiments. In this case, for a fluid of Pr=1, it isverified in simulations that both the ideal straight rolls and spiral-defect chaos are stableattractors in the same parameter regime, and that the initial condition is a decisive factor forwhich one of the two is formed. In the same case, for a fluid of Pr=4, the target patterns aredominant instead of the spirals, the sizes distributions of the target are also notably dependent onthe initial condition.

关 键 词：Rayleigh-Bénard传送模式 数字模拟技术 动力系统 非线性动力系统 平衡模式 

分 类 号：O313[理学—一般力学与力学基础]