Papers by Keyword: DEM Simulation

Abstract: Reduced-iron used rotary spray cooler atomizes cooling water and sprays them directly to the outer wall of the cooler, which is called indirect cooling method for which the motion law of the materials in the cooler will have a great influence on the design and the cooling efficiency of the equipment. Based on the DEM simulation, the motion of materials in the cross section is investigated in two dimensions, and the influences of rotation speed, lifters, particles diameter and drum fill are discussed. The research results will guide the operation in real practice and help to optimize the design and control of the equipment to some extent.

Abstract: Vertical screw conveyor is a kind of main equipments of bulk handing and delivery, and the intermediate support structure is one of the key parts of this equipment. It is necessary to make a research on it for improving the design and optimization to improve bulk delivery efficiency. Degree of freedom theory, analysis software of EDEM with discrete element and setting periodic boundary model are applied in this paper to simulate the vertical screw conveyors grain (rice) delivery process under different intermediate support structure. The results show that traditional intermediate support structure is three times statically indeterminate structure, while the degrees of freedom of new intermediate support is 1; The vertical screw transmission capacity of new type of vertical screw axis machine which uses intermediate spokes structure is slightly decreased, and the driving power required to drive screw axis increases slightly at the same time. The materials axial transport speed is not affected, but the requirement is greatly reduced for the manufacture and installation accuracy.

Abstract: Granular particle damping technique is a means for achieving high structural damping by the use of metal particles filled into an enclosure which is attached to the structure in a region of high vibration levels. The particle dampers are now preferred over traditional dampers due to the stability, robustness, cost effectiveness and the lower noise level than the impact damper. Such a promising technique has been used successfully in many fields over the past 20 years. In this paper, a state-of-art review on the development of modeling for particle damping is presented. The fundamentals and individual features of three main mathematical models of the granular particle damping are briefly summarized, i.e. the lumped mass model, the Discrete Element Method (DEM) and the approach based on the multiphase flow (MPF) theory of gas-particle. It is worth noting that an improved analytical model of the particle damping based on MPF theory is also introduced. The co-simulation of the COMSOL Multiphysics live link for MATLAB is conducted using this improved model. It can be shown that this model makes the complicated modeling problem more simply and offers the possibility to analyze the more complex particle-damping vibrating system.

Abstract: Based on the theory of metal pre-stressing machining, the method of pre-stressing suitable for ceramic materials machining was presented. Using the cluster method, the discrete element method (DEM) model of ceramic materials machining was established. The DEM simulations of cutting process of SiC ceramic under different machining parameters were carried out by orthogonal test design method, and the effects of machining parameters on the number of surface cracks and maximum crack depth after processing were also analyzed. The results showed that the tool edge radius influenced greatly on the number of surface cracks, while the pre-stress influenced greatly on the maximum crack depth.