The role of energetic flow structures on the aeolian transport of sediment and plastic debris  

能量流动结构在风力输送沉积物及塑料废弃物中的作用

作　　者：Manousos Valyrakis Xiaohu Zhao Thomas Pähtz Zhenshan Li Manousos Valyrakis;赵小虎;Thomas Pähtz;李振山

机构地区：[1]Department of Civil Engineering,Aristotle University of Thessaloniki,Thessaloniki 54124,Greece [2]School of Engineering,University of Glasgow,Glasgow G128QQ,UK [3]Division of Environmental Management and Policy,School of Environment,Tsinghua University,Beijing 100084,China [4]Institute of Port,Coastal and Offshore Engineering,Zhejiang University,Zhoushan 316021,China [5]Donghai Laboratory,Zhoushan 316021,China [6]College of Environmental Science and Engineering,Peking University,Beijing 100871,China [7]Key Laboratory of Water and Sediment Sciences,Ministry of Education,Peking University,Beijing 100871,China

出　　处：《Acta Mechanica Sinica》2025年第1期67-81,共15页力学学报(英文版)

基　　金：supported by the National Natural Science Foundation of China (Grants Nos.41171005,41071005,12272344,and 12350710176);the Ministry of Science and Technology of the People’s Republic of China (Grant No.2013CB956000).

摘　　要：Recently,significant progress has been made in conceptually describing the dynamic aspects of coarse particle entrainment,which has been explored experimentally for open channel flows.The aim of this study is to extend the application of energy criterion to the low mobility aeolian transport of solids(including both natural sediment and anthropogenic debris such as plastics),ranging from incomplete(rocking)to full(rolling)entrainments.This is achieved by linking particle movements to energetic flow events,which are defined as flow structures with the ability to work on particles,setting them into motion.It is hypothesized that such events should impart sufficient energy to the particles,above a certain threshold value.The concept’s validity is demonstrated experimentally,using a wind tunnel and laser distance sensor to capture the dynamics of an individual target particle,exposed on a rough bed surface.Measurements are acquired at a high spatiotemporal resolution,and synchronously with the instantaneous air velocity at an appropriate distance upwind of the target particle,using a hot film anemometer.This enables the association of flow events with rocking and rolling entrainments.Furthermore,it is shown that rocking and rolling may have distinct energy thresholds.Estimates of the energy transfer efficiency,normalized by the drag coefficient,range over an order of magnitude(from about 0.001 to 0.0048 for rocking,up to about 0.01,for incipient rolling).The proposed event-based theoretical framework is a novel approach to characterizing the energy imparted from the wind to the soil surface and could have potential implications for modelling intermittent creep transport of coarse particles and related aeolian bedforms.研究人员通过风洞实验研究了塑料球体在风中的移动,以理解湍流如何影响风的运动.他们基于能量和湍流事例开发了一个模型以了解自然粗颗粒沉积物如何开始移动.研究结果表明,湍流风阵通过使颗粒沿风向滚动或以较短摇晃动作导致的蠕变与机械分选来对颗粒移动产生至关重要的作用.这项研究强调了沉积物和塑料碎片夹带的概率性质,并增加了对风力运输过程的理解.

关 键 词：Particle rocking Incipient rolling Wind tunnel experiments Threshold flow energy Aeolian transport Plastics Plastic debris 

分 类 号：P425.1[天文地球—大气科学及气象学]