Models of rotating compressible convection

旋转可压缩对流模型

• 批准号: 418190608
• 负责人: Professor Dr. Andreas Tilgner
• 金额: --
• 依托单位: Institut für Astrophysik und Geophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/418190608?language=en
• 关键词: Models; rotating; compressible; convection

The vast majority of geodynamo models treat the liquid core of the Earth as an incompressible fluid, despite the fact that the core’s density varies by about 20%. This project aims to elucidate the effects of the finite compressibility on convection through numerical simulations. Direct simulation of a compressible core at realistic parameters is not feasible. It is therefore proposed to study compressible convection in a simplified Cartesian geometry, paired with experiments in a gas filled cell in a centrifuge, in order to generate a general understanding of the effects of compressibility. The experiments are performed at the Laboratoire de Géologie de Lyon and can reach more extreme control parameters than the simulations. Only the simulations are the subject of this proposal. The simulations will be run for gases to allow comparison with the experiments, and for equations of state pertinent for condensed matter as they are relevant to geophysics. The most important quantities to be extracted from the simulations are the heat flux and the zonal flow. Zonal flows of alternating direction, inexistent in an incompressible fluid, appear in the compressible case. The transition from 3D to 2D convection induced by rotation will be studied, as well as changes in the flow field when the gas is replaced by a liquid as the convecting fluid.

绝大多数的地球发电机模型将地球的液态核心视为不可压缩的流体，尽管地球核心的密度变化了约20%。本项目旨在通过数值模拟来阐明有限可压缩性对对流的影响。在真实参数下直接模拟可压缩岩心是不可行的。因此，建议在简化的笛卡尔几何中研究可压缩对流，并结合离心机充气池中的实验，以产生对可压缩性影响的一般理解。实验是在里昂实验室进行的，可以获得比模拟更极端的控制参数。只有模拟才是这项提议的主题。这些模拟将用于气体，以便与实验进行比较，以及与凝聚态物质相关的状态方程，因为它们与地球物理有关。从模拟中提取的最重要的量是热通量和纬向流。在不可压缩流体中不存在的交替方向的带状流动在可压缩情况下出现。研究了旋转引起的三维对流到二维对流的转变，以及以液体代替气体作为对流流体时，流场的变化。