中文摘要：

通过流体力学基本方程组的二维数值模拟,探讨了长高比Г=20的矩形腔体中有较强Soret效应的混合流体对流中的局部行波的形成及含有缺陷的局部行波的动力学特性.当分离比ψ=-0.60时,在分叉曲线的鞍结分叉点附近相对Rayleigh数为r=1.926-2.074的范围内,出现了无缺陷局部行波.然后,随r逐渐增加,系统由无缺陷局部行波过渡到含有缺陷的局部行波并在r=2.075-2.224的范围内形成稳定的含有缺陷的局部行波.局部行波对流的宽度随r增加而增加,并在r=2.075处随着对流斑图的转变突然加宽.再随r增加,含有缺陷的局部行波失去稳定,对流控制整个腔体并演化成有缺陷的行波.有缺陷的局部行波是我们发现的新型对流结构.有缺陷的局部行波的形成依赖于局部行波的对流宽度.在具有缺陷的局部行波存在范围内,这种缺陷出现的周期随r增大而增加.

英文摘要：

The researches on nonlinear science currently cause extensive concern all over the world. The natural phenomena which we usually see, such as the convection in atmosphere, the reservoir, the ocean and so on, are all in nonequilibrium open system away from heat equilibrium. The deep research for these phenomena is indispensable both in harmonious coexistence between human and nature, and in controlling, using nature. Rayleigh-Benard convection is one of the typical models for the research of these phenomena. Its experiment is easy to control and the governing equations for convection are well known. Therefore, the research on the convection stability, spatiotemporal structure and the nonlinear dynamics in Rayleigh-Benard convection model has certain representative, theory value and very important practical significance. So far, investigators have got various traveling waves in Rayleigh-Benard convection in binary fluid mixture by experiments and simulations, and found the dynamics of these states. By using a two-dimensional numerical simulation of the fully hydrodynamic equations in this paper, the formation of the localized traveling wave （LTW） without defects and the dynamics of the LTW with defects in convection in binary fluid mixtures with strong Soret effect in a rectangular at the aspect ratio f=20 are studied. The SIMPLE algorithm was used to numerically solve the governing equations consisting of the coupled heat and concentration transfer and fluid flows. The governing equations were solved in primitive variables in a two-dimensional staggered grids with an uniform spatial resolution based on the control （finite） volume method. The power law scheme was used to treat the convective-diffusive terms in the discrete formulation. The discrete equations were solved by an iterative tri-diagonal matrix algorithm （TDMA）. For the separation ratio ψ=-0.60, system appears the LTW without the defects near saddle node of the bifurcation curve for the reduced Rayleigh number r=1.926-2.074. Then, system bec