Rogers JL, Schatz MF, Bougie JL, Swift JB
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
Phys Rev Lett. 2000 Jan 3;84(1):87-90. doi: 10.1103/PhysRevLett.84.87.
We report on the first quantitative observations of convection in a fluid layer driven by both heating from below and vertical sinusoidal oscillation. Just above onset, convection patterns are modulated either harmonically or subharmonically to the drive frequency. Single-frequency patterns exhibit nearly solid-body rotations with harmonic and subharmonic states always rotating in opposite directions. Flows with both harmonic and subharmonic responses are found near a codimension-two point, yielding novel coexisting patterns with symmetries not found in either single-frequency states. Predictions from linear stability analysis of the onset Rayleigh and wave numbers compare well with experiment, and phase boundaries for coexisting patterns track single-frequency marginal stability curves.
我们报告了关于由底部加热和垂直正弦振荡共同驱动的流体层中对流的首次定量观测结果。在刚超过起始点时，对流模式会以与驱动频率呈谐波或亚谐波的方式进行调制。单频模式呈现出近乎刚体的旋转，谐波和亚谐波状态总是沿相反方向旋转。在一个二维余维点附近发现了具有谐波和亚谐波响应的流动，产生了具有在单频状态中均未发现的对称性的新型共存模式。起始瑞利数和波数的线性稳定性分析预测与实验结果吻合良好，共存模式的相边界追踪单频边际稳定性曲线。
