基于CFD-DEM的收获机分离室内谷物运动模拟与试验

采用计算流体力学与离散元耦合的方法对割前摘脱稻麦联合收获机惯性分离室内谷物的运动进行数值模拟。仿真结果表明:籽粒和短茎秆在气流作用下能够实现分离,分离室入口气体速度增加,有助于提高分离室初清选谷物的性能,但入口气体速度增加使得分离室后部气体湍流现象加重,且能耗也随之增加;不饱满籽粒能在分离室内实现沉降。对仿真结果进行了试验验证,结果表明利用CFD-DEM对分离室内谷物运动进行数值模拟是可行的。

Numerical Simulation Based on CFD-DEM and Experiment of Grain Moving Laws in Inertia Separation Chamber

In order to obtain grain moving laws in inertia separation chamber of combine harvester threshing prior to cutting, grains motion was simulated by using computational fluid dynamics and discrete element coupled methods. Simulation results showed that grain particles were separated from short straw through airflow and the performance of chamber separating and cleaning grain was improved with the increasing of airflow velocity, while the turbulence phenomenon in the rear of chamber got more serious and airflow pressure drop was increased. Not full grain particles also deposited in chamber. In order to verify the validity of simulation results, the experimental test was conducted. Experimental results and simulation results were basically accord, which showed that the simulation of grain motion in inertia separation chamber based on CFD-DEM was feasible. The results would be a better basis to improve the performance of inertia separation chamber to separate and clean grain.