Phase classification of laboratory debris flows over a rigid bed based on the relative flow depth and friction coefficients
Phase classification of laboratory debris flows over a rigid bed based on the relative flow depth and friction coefficients
复制标题
根据相对流动深度和摩擦系数对刚性床上实验室泥石流进行相分类
DOI：
10.13101/ijece.1.54
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
K. Miyamoto
中科院分区：
文献类型：
--
作者：
N. Hotta;K. Miyamoto
在泥石流相变分类的初步研究中，整理了泥石流刚性床面摩擦系数的实验数据。将收集的摩擦系数与各种条件下基于沉积物粒径（h/d）的相对流深关系中摩擦系数的理论值进行比较。当h/d值小于20时，泥石流的摩擦系数与由本构方程导出的漂石型泥石流的理论值基本一致;当h/d值在1000-10,000之间时，泥石流的摩擦系数与紊流的理论值基本一致。h/d值为30-300的摩擦系数超过了理论值的碎片和湍流水流。这些中间泥石流中观察到的实验涉及湍流泥流。然而，对这些实验的审查表明，它们可能包括湍流结构不发达的泥石流，可以认为是从层流向湍流过渡的泥石流。在一些过渡型泥石流中，观察到一个界面将流结构分为上顺向流层和下泥石流层，这与载沙流的报告相同。考虑过渡界面的移动，建立了过渡型泥石流的摩擦系数模型。该模型能够解释过渡型泥石流的值，推断泥石流从层流到湍流的相变是由界面的移动引起的。
The friction coefficients of debris flows over a rigid bed from several previous experiments were compiled in a preliminary investigation on the classification of phase transitions in debris flows. The collected friction coefficients were compared to the theoretical values of the friction coefficients in the relationship with the relative flow depth on the basis of sediment particle size (h/d) under various conditions. The friction coefficients of debris flows with h/d values less than 20 agreed closely with the theoretical value for boulder debris flows derived from the constitutive equations, while the friction coefficients with h/d values in the range 1000–10,000 agreed roughly with the theoretical value for turbulent water flows. The friction coefficients with h/d values of 30–300 exceeded the theoretical value for both debris and turbulent water flows. These intermediate debris flows were observed in experiments involving turbulent mud flows. However, a review of these experiments revealed that they may have included debris flows in which the turbulent structure was not well developed, and could be considered as debris flows in transition from laminar to turbulent flows. In some of the transitional debris flows, an interface dividing the flow structure into an upper turbulent-flow layer and a lower debris-flow layer was observed as reported for sediment-laden flows. The friction coefficient for transitional debris flows was modeled considering the shift of this interface. The model was able to explain the value for transitional debris flows, inferring that phase transition in debris flows from laminar to turbulent flows is induced by the shift of the interface.
DOI：
--
发表时间：
2003
期刊：
Journal of Japan society of erosion control Engineering 55-6
影响因子：
--
作者：
Kuniaki Miyamoto;Takahiro Itoh
通讯作者：
Takahiro Itoh
河床粗糙度对泥石流的影响
DOI：
--
发表时间：
2003
期刊：
Journal of Japan society of erosion control Engineering 56-2
影响因子：
--
作者：
Takuro Suzuki;Norihumi Suzuki;Kuniaki Miymoto
通讯作者：
Kuniaki Miymoto