Traveling Wave Convection In Binary Fluid Mixtures In Two-Dimensional Rectangular Cell

The researches of nonlinear science currently cause extensive concern all over the world. The natural phenomena which we usually see, such as the convection in atmosphere, the ocean, the reservoir and so on, are all in nonequilibrium open system away from hot equilibrium. For fluid, if the temperature difference applied across the fluid layer is large enough, the buoyancy function causing instability will exceed the stability of viscosity and hot conduction, the system will appear unsteady convection phenomenon. 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 equation for convection is clear. The Rayleigh-Benard convection is that, in one close channel, the top surface keeps steady temperature and the bottom keeps heated, the temperature difference will cause the fluid convection in channel. Therefore, using Rayleigh-Benard convection model for the research of the convection stability, spatiotemporal structure and the nonlinear dynamics has certain representative, very important significance and theory value.So far, investigators have got various traveing waves in Rayleigh-Benard convection by experiments and calculations. They observed such as traveing wave(TW), blinking traveling wave(BTW), localized traveling wave(LTW), double localized traveling wave(DLTW), stationary overturning convection(SOC), and found the characteristics of these states. This thesis uses two-dimensional hydrodynamic equations to simulate Rayleigh-Benard convection in binary fluid mixtures in two dimensional rectangular cell. According to changing Rayleigh number and computing traveling wave states in different separation ratio and aspect ratio, we have observed steady Counter propagating wave(CPW)state which has not been seen before,TW state with defect and Undulation traveling wave(UTW)state. By the comparison between the same type of traveling waves with different rayleigh number, found out the spatiotemporal structures of different traveling wave state and their ranges, gained the characteristics of these traveling wave states; by the comparison between the same type of traveling waves with different separation ratio and aspect ratio, discussed the dependence of the traveling wave on the separation ratio and aspect ratio.