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Study on fluid dynamics of gaseous transfer in magma chambers

岩浆房气体传输流体动力学研究

基本信息

批准号：
04640732
负责人：
KOYAGUCHI Takehiro
金额：
$ 0.96万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640732/
关键词：
Magma chamber Volcanic gas Multiphase flow Volatile component Magma mixing Particle settling Fractional crystallization Convection

项目摘要

The following two types of experiments were conducted in order to investigate fluid dynamics of gaseous transfer in magma chambers.The first series of the experiments is those on the effect of solid or gas particles on convection in magma chamber using small heavy particles in convecting fluid. The results show that when the concentration of particles is sufficiently small convection is basically unaffected by their presence ; however, when the concentration is above a critical value, the convective motion is considerably altered. Theoretical analyzes suggest that the mode of convection is accounted for the evolution of bulk density of the particle and liquid mixture. This result is published in Journal of Volcanology and Geothermal Research.The second series of experiments were designed to investigate how the gas bubbles migrate into the more viscous upper layr from a less viscous lower layr in a two layr magma chamber which exsolves volatiles as it crystallizes. The results shows that bubbles form a thin form layr at the interface which becomes gravitationally unstable, giving rise to two phase plumes which rise and produce a coarse mixture of the liquid. Theoretical analyzes suggest that the condition for this type of instability should be controlled by the gas flux and diameter of gas bubbles. This result is published in Earth and Planetary Science Letters.These experimental results were applied to phenomena in magma chambers such as origin of layred intrusions. The geological implications of the experiments are discussed and are published in Nature and International Journal of Modern Physics.

为了研究岩浆房中气体迁移的流体动力学，进行了以下两类实验：第一类实验是利用对流流体中的小重粒子研究固体或气体粒子对岩浆房对流的影响。结果表明，当颗粒浓度足够小时，对流运动基本不受颗粒浓度的影响，但当颗粒浓度超过某一临界值时，对流运动发生明显改变。理论分析表明，对流模式占的颗粒和液体混合物的体积密度的演变。这一结果发表在Journal of Volcanology and Geophysical Research上。第二系列实验旨在研究气泡如何从两层岩浆房中较低粘性的下层迁移到较高粘性的上层，该岩浆房在结晶时释放挥发物。结果表明，气泡在界面处形成一层薄形层，由于重力的作用而变得不稳定，产生两相羽流，羽流上升并产生液体的粗混合物。理论分析表明，这种类型的不稳定性的条件应控制的气体流量和气泡的直径。这一结果发表在《地球与行星科学快报》上。这些实验结果被应用于岩浆房中的现象，如层状侵入体的起源。实验的地质意义进行了讨论，并发表在《自然》和《国际现代物理学杂志》上。