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arXiv 1708.02159physics.flu-dyn
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液态金属电池中界面波的耦合与稳定性

Coupling and stability of interfacial waves in liquid metal batteries

Gerrit Maik Horstmann, Norbert Weber, Tom Weier

摘要:

研究了液态金属电池中界面波耦合动力学及其对电池安全运行的影响。与铝电解槽类似,液态金属电池可能对磁流体动力学不稳定性高度敏感,磁流体动力学不稳定性激发能够引起短路的不期望的界面波。然而,在液态金属电池中,波动动力学要复杂得多,因为存在两个可能进入共振的金属-电解质界面。本文的第一部分给出了圆柱形三层电池模型中重力-毛细界面波耦合的势分析。导出了振幅比和波频率的解析表达式,表明波耦合可以用两个独立的无量纲参数来描述。我们提供了一个去耦标准,澄清波耦合将存在于大多数未来的液态金属电池。第二部分通过与多相流直接数值模拟的比较,验证了理论的正确性。对不同的强耦合界面进行了参数研究,分析了系统的稳定性。三种不同的耦合制度,确定涉及特征耦合动力学。对于强耦合接口,我们观察到新的不稳定性,可能有有益的影响的操作安全。

英文摘要:

We investigate the interfacial wave coupling dynamics in liquid metal batteries and their effects to the battery's operation safety. Similar to aluminum reduction cells, liquid metal batteries can be highly susceptible to magnetohydrodynamical instabilities that excite undesired interfacial waves capable to provoke short-circuits. However, in liquid metal batteries the wave dynamics is far more complex since two metal-electrolyte interfaces are present that may step into resonance. In the first part of this paper, we present a Potential analysis of coupled gravity-capillary interfacial waves in a three-layer battery model of cylindrical shape. Analytical expressions for the amplitude ratio and the wave frequencies are derived and it is shown that the wave coupling can be completely described by two independent dimensionless parameters. We provide a decoupling criterion clarifying that wave coupling will be present in most future liquid metal batteries. In the second part, the theory is validated by comparing it with multiphase direct numerical simulations. An accompanying parameter study is conducted to analyze the system stability for differently strongly coupled interfaces. Three different coupling regimes are identified involving characteristic coupling dynamics. For strongly coupled interfaces we observe novel instabilities that may have beneficial effects on the operational safety.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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