在开放通道剪切流下对微塑料运输的数值模拟和实验研究:粒子物理性质和流速的作用
Lulu He1, Jianhao Jiang1, Shiwei Zheng2
1College of Civil Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310023, China.
Ecotoxicology and environmental safety
|November 10, 2024
概括
河流中的微塑料运输取决于流速,颗粒大小和密度. 了解这些因素对于管理水生环境中的微塑料污染至关重要.
科学领域:
- 环境科学 环境科学
- 流体动力学 流体动力学
- 环境化学环境化学
背景情况:
- 在开放通道剪切流中微塑料 (MP) 运输尚未得到充分理解.
- 对MP运输法进行调查对于解决水污染问题至关重要.
研究的目的:
- 在不同流速,密度,尺寸和度下研究微塑料的运输规律.
- 分析粒子特性和流动动力学对MP运动的影响.
主要方法:
- 使用U形实验流体和基于格子博尔兹曼方法 (LBM) 的数值流体.
- 检查了聚乙烯 (PVC) 和聚烯 (PS) 颗粒的运输模式.
主要成果:
- 水平粒子速度和运输距离随流速而增加;垂直速度下降.
- 总平均粒子速度与平均垂直速度相关,无论MP变化如何.
- 粒子加速取决于单个MP类型的尺寸和相对拉力术语 (RDFT),混合类型的密度,RDFT和相对重力术语 (RGT).
结论:
- MP的水平速度与最大横截面流速有很强的相关性,随着MP的大小和度的下降而下降.
- 这些发现为预防和控制河流微塑料污染提供了洞察力.
相关概念视频
Typical Model Studies
340
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
340
Rapidly Varying Flow
51
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
51
Uniform Depth Channel Flow
63
Uniform depth channel flow keeps fluid depth consistent along channels such as irrigation canals. In natural channels, such as rivers, approximate uniform flow is often assumed. This condition occurs when the channel’s bottom slope matches the energy slope, balancing potential energy lost from gravity with head loss due to shear stress. This balance prevents depth changes along the channel length, resulting in a steady, uniform flow.Uniform flow in open channels with a constant cross-section...
63


