摘要
为从颗粒及流场尺度探究沉积物颗粒在水流作用下的悬浮与扩散机制,在离散元中引入高斯曲率模型表征非球颗粒非线性接触特性,并改进非球颗粒的拖曳力模型及孔隙模型,建立了多分散非球颗粒CFD-DEM流固耦合数值方法;通过与物理模型试验对比,验证了该方法的有效性与优越性;随后对沉积物在水流作用下的悬浮扩散过程进行模拟。研究结果表明,沉积物沉降率与颗粒入流量成正相关,与流速成负相关;而逸出率与沉降率呈相反趋势;在高初始排放量下,颗粒团簇效应促进流体动能耗散,颗粒所受重力作用超过惯性力作用,颗粒快速沉降;在低初始排放量下,较高流体动能促进颗粒水平向输运;在流速较小情况下,颗粒形状对沉积物的空间分布影响不可忽略。
To investigate the suspension and diffusion mechanisms of sediment particles under the action of fluids from both particle and flow field scales,a Gaussian curvature model is introduced in the discrete element method to characterize the nonlinear contact properties of non-spherical particles.Additionally,improvements are made to the drag force model and porosity models for non-spherical particles.By doing so,the polydispersed non-spherical particle CFD-DEM coupling numerical method is established.The accuracy and superiority of this model are validated through comparisons with physical experimental results.Subsequently,the suspension and diffusion processes of sediment under fluids are simulated.Results show that the sediment settling rate is positively correlated with the initial discharge quantity of particles and negatively correlated with flow velocity,while the escape rate shows an opposite trend.At high initial discharge,particle clustering effects promote fluid kinetic energy dissipation,causing gravity to surpass inertial forces and leading to rapid particle settling.At low initial discharge,higher fluid kinetic energy enhances horizontal particle transport.At lower flow velocities,particle shape significantly affects the spatial distribution of sediment particles.
作者
杨晔峰
韦桐忠
王胤
YANG Yefeng;WEI Tongzhong;WANG Yin(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2024年第4期669-679,共11页
Advances in Water Science
基金
国家自然科学基金资助项目(51870935)
辽宁省自然科学基金资助项目(2022-KF-18-05)。
作者简介
杨晔峰(1996-),男,江苏常州人,博士研究生,主要从事离散-连续体流固耦合数值方法和深海采矿方面的研究工作。E-mail:yang_yf_1996@mail.dlut.edu.cn;通信作者:王胤,E-mail:y.wang@dlut.edu.cn。
