摘要
【目的】研究垂直风选机的风选参数对谷粒-茎秆混合颗粒体系清选分离效果的影响.【方法】采用DEM(Discrete Element Method)与CFD(Computational Fluid Dynamics)耦合方法模拟了垂直气流下,谷粒-茎秆混合颗粒的风选过程,并对模拟结果进行了试验验证.【结果】低风速范围(5、6、7、8 m/s)下,风速能提高风选后谷粒的体积分数,v=8 m/s时,谷粒体积分数达到100%;高风速范围(11、12、13、14 m/s)下,谷粒出现损失现象,且风速的增大导致损失率变大;v=6 m/s时,谷粒-茎秆混合颗粒的初始体积分数不变,不同下料量之间的风选道内气流分布存在差异,下料量越小,风选后谷粒的体积分数越大,清洁率越高.【结论】采用DEM-CFD耦合技术可以精确模拟谷物风选的复杂物理现象,揭示谷物风选的动力学规律.
【Objective】To study the effect of winnowing parameters of vertical air separator on the cleaning effect of grain-stalk mixed particle system.【Method】DEM(Discrete Element Method)and CFD(Computational Fluid Dynamics)coupling methods were used to simulate the wind separation process of grain-stalk mixed particles under vertical airflow,and the simulation results were verified by experiments.【Result】At a low wind speed range(5,6,7,8 m/s),increasing the wind speed can improve the volume concentration of grains after the winnowing.When v=8 m/s,the volume concentration of grains reaches 100%.At high wind speed range(11,12,13,14 m/s),when v=13 m/s,grain loss occurs,and the increase of wind speed leads to a large loss rate.When v=6 m/s,the initial volume fraction of grain-stalk mixed particles remains the same,and there are differences in airflow distribution in the wind channel between different feeding amounts.The smaller the amount of feeding,the higher the grain volume concentration and the higher the cleaning rate after the winnowing.【Conclusion】The DEM-CFD coupling technology can accurately simulate the complex physical phenomenon of grain winnowing,and reveal the dynamic law of grain winnowing,providing reference for the design.
作者
丁贺贺
石加联
马学东
郭柄江
赵磊
DING He-he;SHI Jia-lian;MA Xue-dong;GUO Bing-jiang;ZHAO Lei(School of Mechanical Engineering,Liaoning University of Science and Technology,Anshan 114051,China)
出处
《甘肃农业大学学报》
CAS
CSCD
北大核心
2019年第6期190-197,共8页
Journal of Gansu Agricultural University
基金
国家自然科学基金项目(5177052111)
关键词
垂直风选
DEM-CFD耦合
风选效果
Vertical air separation
DEM-CFD coupling
the effect of winnowing
