基于CFD-DEM耦合的揉丝机排料装置内物料运动模拟与试验

Numerical simulation and experiment of materials movement based on CFD-DEM coupling method in the discharging device of kneading machine

关键词:  揉丝机  CFD-DEM  耦合  物料运动  数值模拟

Key words:  kneading machine  CFD-DEM  coupling  materials movement  numerical simulation

摘要:

为解决传统物理方法难以对揉丝机排料装置内物料运动进行可视化研究的问题，基于CFD-DEM气固耦合法，采用RNG K-ε湍流模型及Euler-Lagrange耦合算法对揉丝机不同主轴转速下排料装置内物料运动过程、内流道气流速度分布、气流对物料的耦合力分布进行了数值模拟，并对风扇主轴转速3 000 r/min时物料运动过程进行分区域研究。结果表明：在风扇主轴额定转速3 200 r/min范围内，主轴转速2 000、2 500和3 000 r/min在模拟结束时分别排出物料数量为6 191、6 669和7 161个；不同区域内物料平均速度形成梯度分布，由大到小依次为物料出口区域（10.00 m/s）、风扇转动区域（6.00 m/s）、物料入口区域（0.87 m/s）；风扇转动区域气流速度最大（峰值50.00 m/s），对物料耦合力作用最强，物料入口区域则耦合力最小；物料在入口区域内数量最多并在模拟结束时发生少量堆积，在出口区域未见回流现象发生。对模拟结果进行了试验验证，结果表明利用CFD-DEM气固耦合法对揉丝机排料装置内物料运动进行可视化研究是可行的。

Abstract:

It was difficult to do visualization research by traditional physical methods for the materials movement in the discharging device of kneading machine.Based on CFD-DEM gas-solid coupling method,numerical simulation for kneading machine on the process of materials movement in the discharging device under the different spindle velocity,air flow velocity distribution in internal flow field and coupling force distribution that air flow acts on the materials were analyzed by using RNG K-ε turbulence model and Euler-Lagrange coupling algorithm.The materials movement process when fan spindle velocity reached to 3 000 r/min was studied by dividing into different parts.The simulation results showed that:When the rated rotation velocity of fan spindle was within 3 200 r/min,the spindle velocity was 2 000,2 500 and 3 000 r/min.At the end of the simulation,the materials quantities that discharging device produced were 6 084,6 784 and 7 584,respectively;The average velocity of materials in different zones formed a gradient distribution,which in descending order according to speed were materials outlet zone (10.00 m/s),fan rotation zone (6.00 m/s),materials inlet zone (0.87 m/s);The air flow velocity in fan rotation zone was maximum (peak value was 50.00 m/s) and this zone also had the strongest coupling force for the materials,while coupling force in materials inlet zone was the minimum;Quantity of materials in the inlet zone was the maximum and had a small accumulation at the end of simulation,and there was no backflow phenomenon in the outlet zone.In order to verify the simulation results,an experimental test was conducted showing that it was feasible to use CFD-DEM gas-solid coupling method to do visualization research for the materials movement in the discharging device of kneading machine.