ABSTRACT

The behavior of self-organization of convective flows in a thin layer of liquid under point (local) heating is investigated experimentally. The interaction of thermocapillary and thermogravitational-free convection can lead both to self-organization of a cluster of micro-vortices in the form of hexagonal structures and to its partial disintegration. Correlation analysis of the velocity field shows that the characteristic convection scales change continuously over time. The largest size of the vortex flow corresponds to the layer diameter (20 mm); the integral convection scale (2.5 mm) characterizes the established interaction of vortex structures in a wide range of sizes; and the dimensions of hexagonal convective cells (80–100 µm) show the lower limit of the characteristic scale of vortex structures. The observed flow macrostructure is determined by the complex nonlinear interaction of vortices of the specified scales. The resulting value of the average integral convection scale can be effectively used to predict the convection velocity.

摘要

实验研究了在点（局部）加热下液体薄层中对流流动的自组织行为。热毛细管和无热引力对流的相互作用既可以导致以六角形结构形式出现的微涡团簇的自组织，也可以导致其部分分解。速度场的相关分析表明，特征对流尺度随时间连续变化。涡流的最大尺寸对应于层直径（20毫米）。整体对流刻度（2.5毫米）表征了各种尺寸范围内已建立的涡旋结构相互作用。六角形对流池的尺寸（80–100 µm）显示了涡旋结构特征尺度的下限。所观察到的流动宏观结构是由特定尺度的旋涡的复杂非线性相互作用决定的。平均积分对流比例的结果值可以有效地用于预测对流速度。