Defect structures of Rayleigh-Benard travelling wave convection in binary fluid mixtures
Defect structures of Rayleigh-Benard travelling wave convection in binary fluid mixtures
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DOI：
10.7498/aps.58.2528
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发表时间：
2009-04-01
影响因子：
1
通讯作者：
Yu Li
中科院分区：
文献类型：
--
作者：
Ning Li-Zhong;Qi Xin;Yu Li
采用全流体动力学方程的二维数值模拟，研究了含缺陷二元流体混合物中行波对流的动力学特性。当分离比Psi = -0.6时，随着减小瑞利数r的增大，系统由局部行波对流变为有缺陷的行波对流，然后随着r的进一步增大，缺陷消失，变为无缺陷的行波对流。缺陷出现的周期性随着分离比的减小和r的增大而增大，较小的负分离比的增加速率大于分离比。缺陷δ r的存在范围随着Psi绝对值的增大而显著减小。在Psi = -0.11时，缺陷被湮灭，没有发现有缺陷的TW。当r大于r的上限值时，系统由有缺陷的TW转变为无缺陷的TW。而当r小于r的下限值时，不同的Psi值对应不同的TW模式。因此，Psi对模式的形成和模式之间的转变有明显的影响，并且模式之间的转变也很复杂。
By using a two-dimensional numerical simulation of the fully hydrodynamic equations, the dynamics of the traveling wave convection in binary fluid mixtures with defects was studied. For the separation ratio Psi = -0.6, the system changes from localized traveling wave to traveling wave (TW) convection with the defects with increasing reduced Rayleigh number r. Then, the defects disappear and it changes to TW without defects with further increasing r. For different separation ratio Psi, the periodicity of appearance of defects increases with reducing separation ratio and increasing r. The increase rate for a small negative separation ratio is larger than that for separation ratios. The range of existence of defects Delta r remarkably decreases with the absolute value of Psi. At Psi = -0.11, the defects are annihilated and the TW with defects is not found. The system turns to the TW without defects from the TW with defects where r is larger than the upper limit of Delta r. However, different values of Psi correspond to different TW patterns when r is less than the lower limit of Delta r. Therefore, it is obvious that the Psi has influence on the pattern formation and on the transition between the patterns, and the transition between the patterns is also complex.