Rayleigh-Taylor instability of a particle packed viscous fluid: Implications for a solidifying magma
Rayleigh-Taylor instability of a particle packed viscous fluid: Implications for a solidifying magma
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DOI：
10.1029/2004gl021827
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发表时间：
2005-02-11
影响因子：
5.2
通讯作者：
Sumita, I
中科院分区：
文献类型：
--
作者：
Michioka, H;Sumita, I
我们对叠加粘性流体的瑞利-泰勒不稳定性进行了实验室实验，其中上层含有较致密的球形固体颗粒。通过改变粘度和粒径进行了一系列实验，并测量了不稳定性的增长率和波长。这种不稳定性由细小的羽流组成，这些羽流在下降时会合并。观察到羽流间歇性地形成，颗粒层随着时间的推移而变薄，最终以斑点的形式下降。我们发现，增长速率可以通过粘性流体瑞利-泰勒不稳定性的线性稳定性分析来解释，将颗粒床的有效粘度取为流体的20倍，并将上层厚度缩放为颗粒直径的两倍。通过这种缩放，我们发现熔岩湖表面下方的部分固化层可能会因这种机制而变得不稳定。
We performed laboratory experiments of Rayleigh-Taylor instability of superposed viscous fluids where the upper layer contains denser spherical solid particles. A series of experiments are made by varying the viscosity and the particle diameter, and we measure the growth rate and the wave length of the instability. The instability consists of fine-scaled plumes, which coalesce as they descend. Plumes are observed to form intermittently and the particle layer thins with time, which finally descend as blobs. We find that the growth rate can be explained by using the linear stability analysis for Rayleigh-Taylor instability of viscous fluids, by taking the effective viscosity of particle bed to be 20 times that of the fluid, and scale the thickness of the upper layer by twice the particle diameter. Using this scaling, we find that a partially solidified layer beneath the surface of a lava lake may become unstable by this mechanism.