基于CFD-DEM的离散多块石入水-沉降-触底过程数值模拟  

Numerical simulation of the water-entry,free settling and touch-bed process of multiple discrete rocks using the CFD-DEM

作　　者：常姝琪 及春宁[1] 曹永华[2,3,4,5] 岳长喜 CHANG Shuqi;JI Chunning;CAO Yonghua;YUE Changxi(State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University,Tianjin 300350,China;Tianjin Port Engineering Institute,Co.,Ltd.of CCCC First Harbor Engineering Company,Co.,Ltd.,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Ministry of Communications,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Tianjin,Tianjin 300222,China;Tianjin Key Laboratory of Construction,Operation and Maintenance Technologies for Underwater Tunnels,Tianjin 300461,China)

机构地区：[1]天津大学水利工程智能建设与运维全国重点实验室,天津300350 [2]中交天津港湾工程研究院有限公司,天津300222 [3]港口岩土工程技术交通行业重点实验室,天津300222 [4]天津市港口岩土工程技术重点实验室,天津300222 [5]天津市水下隧道建设与运维技术企业重点实验室,天津300461

出　　处：《振动与冲击》2025年第8期160-168,219,共10页Journal of Vibration and Shock

摘　　要：结合有限元离散元方法(finite-discrete element method,FDEM),对计算流体力学(computational fluid dynamics,CFD)软件FLOW-3D进行二次开发,建立了基于CFD-DEM的流固耦合模型,模拟了多块石入水、沉降以及触底的动力过程,分析了不同块石等效直径、形状和入水速度对触底速度和反力的影响。研究发现,块石入水后速度迅速减小,并逐渐趋于定值,随后做动态平衡沉降运动,直至与底面发生碰撞。块石抛填的触底速度随等效直径的增大而增大,不同等效直径下球形块石触底速度绝对值最大,其次是纺锤形块石,最小为圆盘形块石。最大触底反力也随等效直径的增大而增大,成非线性关系,通过拟合得到了触底反力的经验公式。显著性分析结果表明,块石等效直径对触底反力影响最大,其次是块石形状,最小为入水速度。Integrating the combined finite-discrete element method(FDEM)with the computational fluid dynamics(CFD)software FLOW-3D,a CFD-DEM based fluid-solid coupling model was established.This model simulates the dynamic process of multiple rocks entering water,freely settling,and hitting the bottom bed.How different rock equivalent diameters,shapes,and water-entry velocities affect touch-bed velocity and force was analyzed.It was found that rocks’settling velocity decreases rapidly upon water entry,stabilizing before dynamic equilibrium settling and collision with the bottom bed.Touch-bed velocity increases with equivalent diameter,with equant rocks having the highest velocity,followed by rod-shaped rocks,and then disk-shaped rocks.The maximum touch-bed force also increases with equivalent diameter in nonlinear relationships,from which empirical formulae for touch-bed force were derived.Significance analysis showed that the rock’s equivalent diameter has the most significant effect on touch-bed force,followed by shape,and then water-entry velocity.

关 键 词：块石抛填 触底速度 触底反力 联合有限元离散元(FDEM) 流固耦合 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3