Analysis Of Linear Stability And Defect Control In Binary Fluid Mixture Convection

Rayleigh-Benard convection is a common phenomenon occurring in nature, is that, in one close channel, the top surface keeps steady temperature and the bottom keeps heated, the difference temperature will cause the fluid convection in the channel. Rayleigh-Benard convection in binary fluid mixture provides an ideal nonlinear and non-equilibrium system for the studies of stability, bifurcation, complex space-time evolution ,dissipative waves and turbulent.With the perturbation method, the linear stability analysis of Rayleigh-Benard convection in binary fluid mixture was conducted. Based on the normal mode analysis, the characteristic equations were deduced from the perturbation equations of fluid mechanics. Under the free and rigid surface boundary conditions, the characteristic equations were solved, and the critical Rayleigh number, the critical wave number and the critical frequency of the convection were obtained.In this thesis,our main interest focuses on simulating flow for Dimensionless equation by applying the advanced development function of CFD computing software. We obtained some convection patterns, such as travling wave, localized travling wave and counter propagating wave.We analysed their characterstics of spatio-temporal evolution.We also abtained travling wave with defect and analysed their characterstics of spatio-temporal evolution. By heating and cooling the right boundary of the convecting cell, the defect of travling wave were eliminated, and the defectcontrol was achieved primly. However,these control methods disturb the convection near the boundary strongly, need to be improved furthmore.