Pipe Poiseuille flow of viscously anisotropic, partially molten rock
Pipe Poiseuille flow of viscously anisotropic, partially molten rock
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DOI：
10.1093/gji/ggu345
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发表时间：
2014-04
影响因子：
2.8
通讯作者：
J. Allwright;R. Katz
中科院分区：
文献类型：
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作者：
J. Allwright;R. Katz
总结合成的、部分熔融的岩石受到强制变形的实验室实验为测试有关地幔动力学和流变学的假设提供了背景。在这里，我们的假设是，部分熔融地幔的总粘度是各向异性的，这种各向异性来自岩石基质中的偏应力。本文在Takei & Holtzman和Takei & Katz理论的基础上，建立了圆管Poillille流的数学模型。Pipe Poiffille是一种可用于实验室实验的配置，但没有公布结果。我们通过线性化分析和数值模拟对模型系统进行了分析。该分析预测了两种熔体偏析模式：熔体从管中心向管壁的迁移和熔体在管壁附近出现的高孔隙率带中的局部化，与剪切平面成低角度。我们比较我们的结果武井和Katz的平面Poietille流，我们还描述了一个新的近似径向变化的各向异性，提高了自洽模型的武井和Katz。这项研究提供了一套基线，定量预测与未来的实验室实验室实验的强制管Poiffille流的部分熔融地幔。
SUMMARY Laboratory experiments in which synthetic, partially molten rock is subjected to forced deformationprovideacontextfortestinghypothesesaboutthedynamicsandrheologyofthemantle. Here our hypothesis is that the aggregate viscosity of partially molten mantle is anisotropic, and that this anisotropy arises from deviatoric stresses in the rock matrix. We formulate a model of pipe Poiseuille flow based on theory by Takei & Holtzman and Takei & Katz. Pipe Poiseuille is a configuration that is accessible to laboratory experimentation but for which there are no published results. We analyse the model system through linearized analysis and numerical simulations. This analysis predicts two modes of melt segregation: migration of melt from the centre of the pipe towards the wall and localization of melt into high-porosity bands that emerge near the wall, at a low angle to the shear plane. We compare our results to those of Takei & Katz for plane Poiseuille flow; we also describe a new approximation of radially varying anisotropy that improves the self-consistency of models over those of Takei & Katz. This study provides a set of baseline, quantitative predictions to compare with future laboratory experiments on forced pipe Poiseuille flow of partially molten mantle.