Two phase flow in the dynamic Earth: Implications for melt flux and chemical differentiation

在地壳的下部，结晶固体和熔融岩石的混合物可能同时存在。该系统将发展流动不稳定性，以响应不同的强迫，特别是密度差异或构造强迫。可以设想三种基本情况：熔体被“挤出”、“流过”或“积聚”在晶体间的间隙孔隙中，这些情况所“占据”的参数空间将随不同的力、力的组合和熔体-岩石比而不同。学生将专注于解决与理解从深到浅的粘性相通量有关的纯流体力学现象，这驱动了地球内的快速熔体输送和化学分化。学生的目标是建立在理论上和不同的地质相关情况下，在不同的强迫情景下熔体输送的特性和控制参数。为了实现这一目标，学生将应用第一原理流体力学模型的两相流在不同的强迫和探索这些彻底超过一个无量纲的参数空间。特别是，学生将通过重力和/或构造力驱动的非均质多孔介质进行差流的影响的全面研究。该理论的潜在推广包括通过地壳的化学效应的熔体通量预测的影响。

In the lower parts of the Earth's crust, a mixture of crystalline solid and molten rock may exist simultaneously. This system will develop flow instabilities in response to different forcings, specifically to density contrasts or tectonic forcing. Three fundamental situations can be envisaged: melt is either "squeezed out", "fluxed through" or "accumulated in" interstitial pores between crystals, the parameter space that these situations "occupy" will differ with different forcings, force combinations and melt-rock ratios. The student will focus on addressing the pure fluid-mechanical phenomena relating to understanding the flux of the viscous phase from deep to shallow, which drives rapid melt transport and chemical differentiation within Earth. The student will aim to establish the characteristics and governing parameters of melt transport at different forcing scenarios both in theory and in different geologically relevant situations. To reach this aim, the student will apply first-principles fluid-mechanical modelling of two-phase flow under different forcings and explore these thoroughly over a dimensionless parameter space. In particular, the student will perform a comprehensive study of the effects of differential flow through a heterogeneous porous media driven by gravity and/or tectonic forcing. Potential generalizations of the theory include the implications of melt flux predictions through the Earths' crust for chemical effects.