Pattern formation without heating in an evaporative convection experiment
Pattern formation without heating in an evaporative convection experiment
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DOI：
10.1209/epl/i2003-10266-0
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发表时间：
2003-11
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影响因子：
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通讯作者：
H. Mancini;D. Maza
中科院分区：
文献类型：
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作者：
H. Mancini;D. Maza
我们提出了一个重现自然界中挥发性流体条件的单流体层蒸发实验。当与蒸发相关的潜热足够大时，通过该层自由表面的热流产生温度梯度，可以破坏导电静止状态，从而在没有任何外部加热的情况下产生对流细胞结构。然后可以在从初始深度值到最小阈值深度的瞬态蒸发范围内观察到对流细胞，此后出现导电不动状态，直到蒸发结束并进行脱湿序列。在没有加热的情况下，这里得到的对流模式序列与b<s:1>纳德-马兰戈尼对流中得到的序列相似。这项工作提出了空间分岔序列作为层深度的函数。从非蒸发实验中已知的正方形到六边形图案的转变，在这里得到了类似的波长变化。
We present an evaporation experiment in a single fluid layer reproducing conditions of volatile fluids in nature. When latent heat associated to the evaporation is large enough, the heat flow through the free surface of the layer generates temperature gradients that can destabilize the conductive motionless state giving rise to convective cellular structures without any external heating. Convective cells can be then observed in the transient range of evaporation from an initial depth value to a minimum threshold depth, after which a conductive motionless state appears until the evaporation finishes with an unwetting sequence. The sequence of convective patterns obtained here without heating is similar to that obtained in Bénard-Marangoni convection. This work presents the sequence of spatial bifurcations as a function of the layer depth. The transition between square-to-hexagonal pattern, known from non-evaporative experiments, is obtained here with a similar change in wavelength.