混凝土搅拌筒CFD-DEM多相流数值模拟与分析

Numerical Simulation and Analysis on Multi-Phase Flow in Concrete Mixing Drum with CFD-DEM

为研究混凝土运输车搅拌筒内的混凝土与骨料颗粒的真实运动情况,采用CFD-DEM耦合的方法,考虑混凝土的非牛顿流体特性及骨料颗粒间的相互作用,对混凝土进料、搅拌、出料过程的混凝土及颗粒运动规律进行数值模拟。通过将出料时间和出料速率数值仿真结果与实验对比,验证了CFD-DEM耦合方法的可行性。将计算流体动力学(Computational Fluid Dynamics,CFD)和离散元(Discrete Element Method,DEM)仿真结果导入ABAQUS中对叶片结构强度进行了分析,结果表明:叶片所受应力远小于材料的许用应力,最大节点位移满足刚度设计要求。最后对叶片的磨损情况进行了分析。

In order to study the real movement of concrete and aggregate particles in the mixing drum,and considering the non-Newtonian fluid characteristics of concrete and the interaction between aggregate particles,computational fluid dynamics and discrete element method(CFD-DEM)were used to simulate the movement laws of concrete and particles in the process of concrete feeding,mixing and discharging.By comparing the numerical simulation results of discharge time and discharge rate with the experiment,the feasibility of CFD-DEM coupling method is verified.The CFD and DEM simulation results were imported into ABAQUS to analyze the structural strength of the blade.The results show that the stress on the blade is far less than the allowable stress of the material,and the maximum node displacement meets the stiffness design requirements.Finally,the wear condition of the blade and the mixing drum were analyzed.