Thermal Convection in a Thermosensitive Viscous Fluid with Inhomogeneous Cooling
Thermal Convection in a Thermosensitive Viscous Fluid with Inhomogeneous Cooling
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DOI：
10.7566/jpsj.86.043402
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发表时间：
2017-04-15
影响因子：
1.7
通讯作者：
Kurita, Rei
中科院分区：
文献类型：
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作者：
Kobayashi, Kazuya U.;Oikawa, Noriko;Kurita, Rei
热敏性粘性流体在自然界中普遍存在。例如，地幔中的流体与粘度强烈依赖于温度的系统有很大的相似之处。在这样的系统中可以观察到有趣的现象，例如，在对流中形成停滞区。然而，尽管它们无处不在，但对这些流体中的热对流动力学的清楚理解仍然不清楚，特别是在空间条件不均匀的情况下。在这里，我们报告了当明胶溶液在顶部表面以非均匀方式冷却时的独特热对流。表面自发形成一块楔形的滞流“盖子”，底部形成大小不一的对流。可以看到漩涡在流动中从小环路移动到大环路，并稳步向下倾斜到较大的漩涡。我们认为这是由于旋涡之间的流动速度不同造成的。
Thermosensitive viscous fluids are ubiquitous in nature. Fluids in the mantle, for example, bear a strong resemblance to systems whose viscosity strongly depends on temperature. Interesting phenomena can be observed in such systems, e.g., the formation of a stagnant domain in convective flows. Yet despite their ubiquity, a clear understanding of thermal convection dynamics in these fluids remains unclear, especially when conditions are inhomogeneous in space. Here, we report unique thermal convection when a gelatin solution is cooled in a non-uniform manner at the top surface. A wedge-shaped stagnant "lid" is spontaneously formed at the surface, and convective flows of different sizes are formed at the bottom. Vortices are seen to move from small to large loops in the flow, and flows downwards steadily slant towards the larger vortex. We believe that these are due to the difference in flow velocity between vortices.