Numerical investigation of the dynamics of flexible vegetations in turbulent open-channel flows

作     者：Dong Xu Jia-ning Liu Yun-feng Wu Chun-ning Ji Dong Xu;Jia-ning Liu;Yun-feng Wu;Chun-ning Ji

作者机构：State Key Laboratory of Hydraulic Engineering Simulation and SafetyTianjin UniversityTianjin 300072China 

出 版 物：《Journal of Hydrodynamics》 (水动力学研究与进展B辑（英文版）)

年 卷 期：2022年第34卷第4期

页      面：681-699页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：the National Natural Science Foundation of China(Grant Nos.5217090155 51979186 and 51779175) 

主　　题：Flexible vegetation dynamic responses flow-induced vibration(FIV) fluid-structure interaction(FSI) 

摘      要：Aquatic vegetations widely exist in natural rivers and play an essential role in the evolution of the water environment and ecosystem by changing the river’s hydrodynamic characteristics and transporting sediments and *** reality,most aquatic vegetations are highly flexible,which invalidates the“rigid-cylinderassumption widely adopted in many *** explore the dynamics of submerged flexible vegetation in open-channel flows and its feedback to turbulent flow structures,numerical simulations are carried out using an in-house fluid-structure interaction(FSI)*** the simulations,the geometry of vegetation plants is grid-resolved,the turbulent flow is simulated using the large eddy simulation(LES),the dynamics of the flexible plants are solved using the vector form intrinsic finite element(VFIFE)method,and the turbulent flow and the plants are two-way coupled using the immersed boundary(IB)*** dynamic responses of the flexible vegetation with different plant flexibility,spacing,and submergence are *** results show that flexible plants are subjected to complex flow-induced vibrations(FIVs)rather than static *** FIV involves both streamwise and cross-flow motions driven by the small-scale vortex shedding around the plants and the large-scale Kelvin-Helmholtz(K-H)vortices developed in the vegetation canopy *** vegetations exhibit pulsive wave motion of different patterns in relatively long and narrow open *** with the open-channel flows with static plants with equivalent bending deformation,the dynamic responses of flexible plants may increase the turbulent Reynolds stress of the open-channel flow by 70%–100%and increase the invasion depth of the K-H vortices by 30%–50%.