Huke B, Pleiner H, Lücke M
Institut für Theoretische Physik, Universität des Saarlandes, D-66041 Saarbrücken, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Oct;78(4 Pt 2):046315. doi: 10.1103/PhysRevE.78.046315. Epub 2008 Oct 29.
We have numerically investigated Rayleigh-Bénard convection in binary mixtures assuming a thermal diffusion ratio that depends on the local temperature and changes its sign within the cell. The stationary instability has been found to precede the oscillatory one for a wide range of negative mean psi values. The bifurcation diagram for stationary rolls turns out to be qualitatively different from that for constant Soret effect. Nevertheless, it can be mapped onto this special case by using a scaling argument, taking into account the fact that for small convection amplitudes the rolls are restricted to parts of the cell where the sign of the Soret coefficient favors instability.
我们对二元混合物中的瑞利 - 贝纳德对流进行了数值研究，假设热扩散比取决于局部温度并在单元内改变其符号。已发现对于广泛的负平均ψ值范围，静态不稳定性先于振荡不稳定性出现。静态滚动的分岔图在定性上与恒定索雷特效应的分岔图不同。然而，考虑到对于小对流振幅，滚动被限制在索雷特系数符号有利于不稳定性的单元部分这一事实，通过使用标度论证，它可以映射到这个特殊情况。
