颗粒流体与固体壁的相互作用:对茶效应的研究
Yishan Hong1, Hongyi Zou1, Lijun Yang1,2
1School of Astronautics, Beihang University, Beijing 100191, China. dongry@buaa.edu.cn.
Soft matter
|April 9, 2025
概括
颗粒状流在固体边缘上表现出复杂的动态,分裂成分散和均的区域. 粒子凝聚力可以控制流动模式和分散,为粒子主导的流提供了洞察力.
科学领域:
- 物理 物理学 物理
- 流体动力学 流体动力学
- 材料科学 材料科学 材料科学
背景情况:
- 颗粒流与固体边界相互作用,使动态和自然/工业现象复杂化.
- "茶效应"已知用于液体,但在颗粒流中类似现象的研究较少.
研究的目的:
- 为了实验性地研究颗粒流动与形固体边缘的相互作用.
- 了解尾行边缘在流动行为和分散中的作用.
- 开发一种用于预测和控制颗粒流散的方法.
主要方法:
- 在形边缘上对颗粒流量的实验研究.
- 系统调整参数:倾斜角度,粒子直径,边缘半径和表面粗度.
- 开发和应用一个无维数用于分散预测.
主要成果:
- 固体边界的尾行边缘显著影响颗粒流,导致速度不均.
- 流量分裂成不同的"分散"和"均"区域.
- 导出了一个无维数,并成功预测了颗粒流散.
- 增加的粒子凝聚力将流量从异质结构转移到谷物集群.
结论:
- 在复杂边界的颗粒式流动动力学中,尾行边界至关重要.
- 一个无维数有效地预测并允许调节颗粒流散.
- 粒子凝聚力提供了一个切换流动模式和控制分散的机制.
- 这些发现为在固体边界上以粒子为主导的流动动力学提供了新的见解.
相关概念视频
Flow Table Test
99
The flow table test is an established method used to assess the workability of concrete, particularly useful for evaluating highly flowable concrete mixes. This test employs an apparatus that consists of a wooden board topped with a steel plate, collectively weighing 35 pounds. The board is connected to a base via a hinge and measures 27.6 inches on each side.
Concrete is placed within a truncated cone mold that is 8 inches high with an 8-inch base diameter and a 5-inch top diameter. The...
Concrete is placed within a truncated cone mold that is 8 inches high with an 8-inch base diameter and a 5-inch top diameter. The...
99
Steady, Laminar Flow in Circular Tubes
95
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is...
95
General Characteristics of Pipe Flow I
537
Pipe flow refers to the movement of fluids within fully enclosed conduits, typically cylindrical in shape, such as water pipes or hydraulic hoses. These conduits are designed to withstand high-pressure gradients that drive fluid movement, contrasting with open-channel flows, where gravity is the primary driving force. Rectangular conduits, like air conditioning and heating ducts, generally operate at lower pressures and are less suited for high-pressure applications.
The classification of fluid...
The classification of fluid...
537
General Characteristics of Pipe Flow II
510
When fluid enters a pipe, it first passes through the entrance region, where the velocity profile adjusts due to viscous effects. In this region, a boundary layer forms along the pipe walls and grows until it fully occupies the pipe's cross-section. Once the boundary layer merges, the flow becomes fully developed, with a steady velocity profile that remains consistent along the pipe's length.
The distance to reach a fully developed flow is called the entrance length and depends on the...
The distance to reach a fully developed flow is called the entrance length and depends on the...
510
Viscosity
5.7K
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
5.7K
Plane Potential Flows
192
Plane potential flows simplify fluid motion by assuming the fluid to be irrotational and incompressible. These characteristics allow these flows to be described by a velocity potential function, ϕ, representing the flow speed in a given direction, and a stream function, ψ, that visualizes the flow path, both governed by Laplace's equation. These parameters help in estimating flow patterns, velocity distributions, and pressure fields around various hydraulic structures.
Uniform...
Uniform...
192


