透水性碎石丁坝绕流及块体受力的数值模拟  

Numerical simulation of flow around permeable rubble spur dike and blocks stress distribution

作　　者：李有为 LI You-wei(Changjiang Waterway Planning,Design and Research Institute,Wuhan 430040,China)

机构地区：[1]长江航道规划设计研究院,湖北武汉430040

出　　处：《水运工程》2021年第11期98-104,共7页Port & Waterway Engineering

摘　　要：碎石丁坝常用于河道的水流调控,其水动力学特征是评估工程效应的重要依据。流固耦合数值模型可有效地用于模拟相关的水动力学过程,描述其力学特征。建立了带自由表面多孔介质水流模型和离散单元法相耦合的CFD-DEM数值模型,并依据试验数据对模型进行有效性及模拟精度的验证。利用该数值模型开展碎石丁坝绕流的数值模拟,研究结构透水性对局部流动和碎石体受力的影响。研究结果表明:1)随着丁坝透水性的增强,尾流区沿流向延长。2)不同坝体透水性条件下的主流区及尾流区的速度分布有明显的差异,但尾流区内的剪切流速的分布具有一定的相似性。3)丁坝结构受力分析显示,随着坝体透水性的增强,块体受力区域由坝头向坝身蔓延、受力区面积逐渐增大。Rubble spur dike is a common hydraulic structure used in water regulation whose hydrodynamics characteristics of the spur is an important reference to related engineering assessment.Fluid-solid coupling model is a powerful tool used to simulate corresponding hydrodynamic process and describe the mechanical characteristics.A CFD-DEM numerical model is established,which is a coupling of water flow model in a porous medium with free surface and discrete element method.The validity and simulation accuracy of the model are verified based on experimental data.Using this numerical model,the numerical simulation of the flow around the rubble spur dike is carried out,and the influence of the structural water permeability on the local flow and the force of the rubble body is studied.The results show that:1)As the water permeability of the spur dike increases,the wake area extends along the flow direction.2)The velocity distributions of the main flow zone and the wake zone under different water permeability conditions of the dam body are obviously different,but the shear velocity distribution in the wake zone has a certain similarity.3)The force analysis of the spur dike structure shows that as the water permeability of the dike body increases,the force area of the block spreads from the dike head to the dike body,and the force area gradually increases.

关 键 词：碎石丁坝 绕流特性 结构受力 CFD-DEM(计算流体动力学和离散单元法)耦合模型 自由表面水流 

分 类 号：U656.3[交通运输工程—港口、海岸及近海工程]