A granular energy-controlled boundary condition for discrete element simulations of granular flows on erodible surfaces
A granular energy-controlled boundary condition for discrete element simulations of granular flows on erodible surfaces
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DOI：
10.1016/j.compgeo.2022.105115
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发表时间：
2023-02
影响因子：
5.3
通讯作者：
Chongqiang Zhu;Yu Huang;Jin Sun
中科院分区：
文献类型：
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作者：
Chongqiang Zhu;Yu Huang;Jin Sun
底质的卷吸作用经常发生，它可以使地球物理流的体积增加许多倍，并极大地影响其流动性。尽管已经进行了许多大规模的研究来调查流动过程中的夹带，但迫切需要颗粒尺度的研究来了解这一复杂的过程。本文提出了一种新的能量控制边界模型，用于模拟易蚀表面上的倾斜颗粒流，旨在研究夹带颗粒流的流变特性。通过调节底部颗粒床的能量来控制冲刷程度。系统地分析了体积速度、应力、微观结构和本构行为。我们的模拟捕捉指数衰减的速度在蠕动区域，确认这种配置可以应用于研究地球物理流夹带。自由面流速随冲刷深度的增加而增加，这意味着卷吸可以大大增强颗粒流的流动性。然而，剪切带中的流动仍然属于惯性区。新的能量控制配置提供了有效的和高效的方式来调查颗粒流的侵蚀表面，作为第一步，以了解地球物理流涉及夹带，这是必不可少的开发新的地质灾害减灾战略。
Entrainment of the substrate, which can cause the volume of geophysical flows to increase by many times and greatly affects its mobility, occurs frequently. Even though many large-scale studies have been conducted to investigate entrainment during flows, particle-scale studies are urgently needed to understand this complex process. We propose a novel configuration with an energy-controlled boundary to model inclined granular flows on erodible surfaces with the aim of investigating the rheological features of granular flows with entrainment. The erosion degree is controlled by adjusting the energy of the bottom granular bed. The bulk velocity, stress, microstructure, and constitutive behavior are systematically analyzed. Our simulations capture the exponentially decaying velocity in the creeping region, confirming that this configuration can be applied to study geophysical flows with entrainment. The velocity at the free surface increases with erosion depth, which means entrainment can greatly enhance the mobility of granular flow. However, the flow in the shear band still belongs to the inertial regime. The novel energy-controlled configuration provides effective and efficient way to investigate granular flows on erodible surfaces, serving as an initial step to understand geophysical flows involving entrainment, which is essential to develop new geo-disaster mitigation strategy.