The dynamical behavior of a localized traveling wave (LTW) in a binary fluid layer heated from below confined in a rectangular cell with the intermediate aspect ratio Γ=12 and the separation ratio ψ=-0. 11 is studie...The dynamical behavior of a localized traveling wave (LTW) in a binary fluid layer heated from below confined in a rectangular cell with the intermediate aspect ratio Γ=12 and the separation ratio ψ=-0. 11 is studied by using the two-dimensional numerical simulation of the full hydrodynamic equations. We find that a counterpropa-gating wave (CPW) occurs at the onset of convection and is modulated in space-time. The modulated traveling wave (MTW) plays an important role in the transition to the LTW state, and the LTW state depends on the fluid parameters and exists in a narrow interval of the reduced Rayleigh number. The transition from LTW to an extended traveling wave (ETW) or stationary overturning convection (SOC) state occurs when r exceeds a certain critical value. Our results agree with those observed in experiments.展开更多
We have performed numerical simulations of localized travelling-wave convection in a binary fluid mixture heated from below in a long rectangular container. Calculations are carried out in a vertical cross section of ...We have performed numerical simulations of localized travelling-wave convection in a binary fluid mixture heated from below in a long rectangular container. Calculations are carried out in a vertical cross section of the rolls perpendic- ular to their axes. For a negative enough separation ratio, two types of quite different confined states were documented by applying different control processes. One branch of localized travelling waves survives only in a very narrow band within subcritical regime, while another branch straddles the onset of convection existing both in subcritical and super- critical regions. We elucidated that concentration field and its current are key to understand how confined convection is sustained when conductive state is absolutely unstable, The weak structures in the conducting region are demonstrated too.展开更多
文摘The dynamical behavior of a localized traveling wave (LTW) in a binary fluid layer heated from below confined in a rectangular cell with the intermediate aspect ratio Γ=12 and the separation ratio ψ=-0. 11 is studied by using the two-dimensional numerical simulation of the full hydrodynamic equations. We find that a counterpropa-gating wave (CPW) occurs at the onset of convection and is modulated in space-time. The modulated traveling wave (MTW) plays an important role in the transition to the LTW state, and the LTW state depends on the fluid parameters and exists in a narrow interval of the reduced Rayleigh number. The transition from LTW to an extended traveling wave (ETW) or stationary overturning convection (SOC) state occurs when r exceeds a certain critical value. Our results agree with those observed in experiments.
文摘We have performed numerical simulations of localized travelling-wave convection in a binary fluid mixture heated from below in a long rectangular container. Calculations are carried out in a vertical cross section of the rolls perpendic- ular to their axes. For a negative enough separation ratio, two types of quite different confined states were documented by applying different control processes. One branch of localized travelling waves survives only in a very narrow band within subcritical regime, while another branch straddles the onset of convection existing both in subcritical and super- critical regions. We elucidated that concentration field and its current are key to understand how confined convection is sustained when conductive state is absolutely unstable, The weak structures in the conducting region are demonstrated too.
