混合流体Rayleigh-Bénard对流是研究非平衡对流的非线性动力学特性的典型模型之一.基于流体力学方程组的数值模拟,首先探讨了矩形腔体中具有强Soret效应(分离比Ψ=−0.60)的混合流体行波对流的分叉特性及斑图演化,沿着分叉曲线的上部分支,随着相对瑞利数的增加,此系统依次出现了局部行波对流、具有缺陷的行波对流、行波对流、摆动行波对流及定常对流5种行波对流解.然后,研究了分离比Ψ对对流解的影响,与弱Soret效应(Ψ=−0.11)时的对流解相比较,强Soret效应(Ψ=−0.60)时出现的对流解更丰富.由于有强Soret效应的对流的复杂性,Ψ=−0.60时的对流解与Ψ=−0.20,−0.4时的对流解不同.%The Rayleigh-Bénard convection in a binary fluid mixture is one of typical models for studying the nonlinear dynamics of nonequilibrium convection. In this paper, using the numerical simulations of the two-dimensional full equations of hydrodynamics, we study the bifurcation and evolution of patterns in the traveling wave convection in binary fluid mixtures with strong Soret effect (separation ratioΨ =−0.60) in a rectangular cell. The system exhibits 5 types of traveling wave convection solutions with the increasing of reduced Rayleigh number r along the upper branch of the bifurcation curve. They are localized traveling wave convection, traveling wave convection with defects, traveling wave convection, undulation traveling wave convection, and stationary overturning convection. Second, the influence of separation ratio on convection solutions is investigated. By comparing the convection solutions with strong Soret effect (Ψ =−0.60) with those of weakly Soret effect (Ψ =−0.11), we find that those with strong Soret effect are richer. Because of the complexity in convection with strong Soret effect, the convection solutions at Ψ = −0.60 are different from those atΨ =−0.20,−0.4.
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