On the Dimension of Cellular Vortices caused by Convection

[摘要] It is well known that when a thin horizontallayer of a fluid heated gradually from below, the stream caused by convection makes well-ordered cellular vortices under a certain condition. Although the condition has been investigated theoretically and experimentally by many authors there are still want of knowledge about the dimension of the cells.In the present study, the average diameter of the vortices were measured by counting the number of cells in a given area. The cells were made in the liquid mixture of benzene petroleum B and carbon tetrachloride, and aluminium powder was suspended in it in order to make the cells visible. The results are shown in Figs. 3 and 4.It was found that the diameter d increased with increasing h, the thickness of the layer, and with increasing Δθ, the temperature difference between the top and the bottom of the layer. The effect of the former was stronger than that of the latter. It was proved that the ratio d/h cannot be represented by a function of the single variable λ (_??_8Δθ), a dimensionless quantity defined in the text.

[学科分类] 大气科学