基于固液两相流模型的泥石流流速垂向分布研究

泥石流流速的垂向分布是泥石流运动理论中的核心问题之一。以固液两相流模型为基础,分析了泥石流中两相速度相等与不等条件下的本构关系和泥石流流速垂向分布的计算方法;在二维恒定均匀流的条件下,考虑两相之间的相互作用,推导层流和紊流流态下泥石流中液相和固相速度的垂向分布公式,并采用不饱和水石流的试验数据进行了验证。结果表明:泥石流两相之间的速度差异是描述两相之间相互作用的根本所在;泥石流固相浓度与本构关系中的模化参数均有关联,是流速垂向分布计算中的重要参量;基于两相流模型的泥石流流速垂向分布公式比现有公式更具普遍意义,且其计算结果能与试验数据较好吻合。

Study of vertical velocity distribution in debris flow based on solid-liquid two-phase flow model

The vertical velocity distribution of debris flow is one of the key parts of its kinematics. Based on the solid-liquid two-phase flow model, the constitutive relation of debris flow with equal or unequal two-phase velocity was analyzed,and the calculation methods for the vertical velocity distribution were studied. Under the assumption of two-dimensional steady uniform flow, the vertical velocity distribution formula of the solid and liquid phases was deduced in the laminar and turbulent flow regime,and the experimental data of the unsaturated stony debris flow was used to verify the formula. The result indicates that the two phase velocity difference is the nature of the characteristic of the interaction between the solid and liquid phases,and the solid-volume fraction which plays an important role in the vertical velocity distribution calculation is associated with the modular parameters in the constitutive equations. The solid-liquid model-based vertical velocity distribution formula has a more general meaning than the existing formulas, and the calculated value of the formula agrees well with the experimental data.