双组分混合流体中Eckhaus不稳定调谐的行波对流

Traveling-wave convection with Eckhaus instability modulation in a binary fluid mixture

在双组分混合流体的Rayleigh-B啨nard对流系统中,数值模拟获得了周期性时空位错缺陷调谐的扩展行进波对流状态.研究了该状态的时空演化特性.结果表明,Eckhaus不稳定触发的对流涡卷对的产生是调谐的起源,对流涡卷在边界处生成与湮没频率的不同,又使系统返回不稳定区域,系统在稳定与不稳定的波数之间振荡.还探讨了一个周期内传热与混合特性的改变及其控制参数的变化规律.

For Rayleigh-Bénard convection in a binary fluid mixture, we obtained a traveling-wave state with periodic modulation of spatiotemperal dislocation defects in a rectangular cell by the numerical simulation of full hydrodynamic equations. The investigations show that the creation of pairs of convective roils triggered by Eckhaus instability leading to this modulation. Because the generating frequencies of rolls at the left wall smaller than the annihilating frequencies of rolls at the right wall, the system soon move out of the stable region, in this way the system oscillates back and forth between the stable and unstable Echkaus wave number band. The properties of heat transfer and fluid mixing also studied too.