Effects of Horizontal Flow on Perturbation Growth and Convection Periodicity
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摘要: 对Pr=0.0272的纯流体在矩形腔体外加水平来流时,进行二维流体力学基本方程组的数值模拟.研究了该纯流体Rayleigh-Benard对流的一维行波斑图的成长及时空的演化.发现对流成长过程可以划分为3个阶段,即对流发展、对流指数成长和周期变化。在对流指数成长阶段对不同相对Rayleigh(瑞利)数Rar的最大垂直流速场随时间变化的情况进行分析,获得了最大垂直流速场指数成长阶段的线性成长率γm和相对Rayleigh数Rar的关系公式.研究了行波周期受水平来流Reynolds(雷诺)数的影响,揭示了行波对流周期性及其对水平来流Reynolds数的依赖性.
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关键词:
- Rayleigh-Benard对流 /
- 成长率 /
- 时空斑图 /
- 周期性
Abstract: Numerical simulation of the 2D fully hydrodynamic equations for the pure fluid in a rectangular channel with horizontal flow for Prandtl number Pr=0.0272 was conducted. Growth and spatiotemporal evolution of the 1D traveling wave patterns in the RayleighBenard convection of the pure fluid were investigated. It is found that the convective growth process can be divided into 3 stages: the development stage, the exponential growth stage and the periodic variation stage. Through analysis on the variation of the maximum vertical velocity field with time for different relative Rayleigh numbers Rar in the exponential growth stage, a formula of variation of linear growth rate γm was obtained with respect to Rar. Furthermore, the traveling wave convection periodicity and its dependence on the horizontal flow Reynolds number were revealed.-
Key words:
- Rayleigh-Benard convection /
- growth rate /
- spatiotemporal pattern /
- periodicity
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