不同粒径组合块石群水下漂移数值模拟

Numerical simulations of drifting of rock groups with different particle diameter combinations

中文关键词: CFD DEM耦合方法  流体-颗粒相互作用  抛石  漂移  扩散

英文关键词: coupled CFD-DEM method  fluid-particle interaction  riprap  drift  diffusion

中文摘要:

      抛石漂移是河道治理、护岸、潜丁坝、桥墩防冲等实际工程中经常遇到的问题．针对抛石颗粒在水中的漂移，采用计算流体力学(CFD)与离散元方法(DEM)耦合的方法，建立了颗粒流数值模型，并采用物理模型试验结果对数值模型的正确性进行验证．为研究级配对块石群水下漂移的影响，对不同粒径组合的块石群抛石漂移进行计算，对块石群在底床上的落点分布形态和扩散范围、漂距、分布面积等进行分析．计算结果表明，同一规格的块石群，其级配组成的均匀性和连续性越好，平均漂距和分布面积越大．

英文摘要:

      Riprap drifting is a problem encountered frequently in the actual projects of river channel regulation, bank protection, submerged spur dike construction and pier scour protection. A particle laden flow numerical model is built by coupling computational fluid dynamics (CFD) and discrete element method (DEM) to analyze the drifting of riprap particle in water flow. Comparisons are carried out with experimental results of physical model to verify the numerical model. In order to investigate the effect of gradation on the drifting of rock group in water flow, calculations of riprap drifting of rock group with different particle diameter combinations are performed. The distribution pattern and diffusion bound of rock group falling point on bed, drift distance and distribution area are analyzed. The results show that for the rock group with the same specification, the better the uniformity and continuity of the gradation of rock group are, the larger the average drift distance and the distribution area are.