Study on induced airflow law of grab unloading based on CFD-DEM

Grab bucket unloading is an important link in the process of grain transportation in ports, and the airflow changes caused by particle movement are a key influencing factor causing dust overflow. At present, there are few studies on the induced airflow changes during grab unloading. This article uses the CFD-DEM coupling method to study the effects of two major factors, mass flow rate and drop height, on the induced airflow. The results show that under this model, the induced airflow velocity increases with the increase of mass flow rate and drop height, and the power exponents of the fitting curve are about 0.25 and 0.44, respectively. Among the two major factors, the drop height plays a dominant role, When the mass flow rate is small (model 2.14 Kg/s in this article), the impact of the change in drop height on the induced airflow velocity is relatively small. As the mass flow rate increases, the impact of drop height increases. Based on the dimensional analysis method and combined with the simulation results, the empirical formula of the induced airflow velocity is established, which can provide a reference for the structural design of the port dust funnel.