Experiments on the stability of convection rolls in fluids whose viscosity depends on temperature
Experiments on the stability of convection rolls in fluids whose viscosity depends on temperature
复制标题
粘度随温度变化的流体中对流辊的稳定性实验
DOI：
10.1017/s0022112078002736
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发表时间：
1978
影响因子：
3.7
通讯作者：
F. Richter
中科院分区：
文献类型：
--
作者：
F. Richter
本文研究了二维对流辊的稳定性随瑞利数、波数和粘度变化的函数关系。实验使用的波数，瑞利数高达25 000和粘度的变化高达约20倍的控制初始条件。稳定辊的参数范围是由一个六角形细胞制度在小瑞利数和粘度的大变化。否则，辊经受与已经在均匀粘度的流体中研究的相同的转变。双峰不稳定性导致一个稳定的三维图案发生在较小的平均瑞利数值的粘度增加的变化。这似乎是与原始辊相关的温热边界层的低粘度的结果。
The stability of two-dimensional convection rolls has been studied as a function of the Rayleigh number, wavenumber and variation in viscosity. The experiments used controlled initial conditions for the wavenumber, Rayleigh numbers up to 25 000 and variations in viscosity up to a factor of about 20. The parameter range of stable rolls is bounded by a hexagonal-cell regime at small Rayleigh numbers and large variations in viscosity. Otherwise, the rolls are subject to the same transitions as have already been studied in fluids of uniform viscosity. The bimodal instability leading to a stable three-dimensional pattern occurs at smaller values of the average Rayleigh number as the variations in viscosity increase. This appears to be a consequence of the low viscosity of the warm thermal boundary layer associated with the original rolls.