شبيه سازي عددي رفتار ديناميكي مواد دانه اي كشاورزي در محيطهاي گسسته با ارايه مدلي با المان هاي مجزا

Numerical Simulation of the Dynamic Behaviour of Agricultural Particulate Materials Using a Suitable Discrete Element Model

One of the most important factors in the accuracy of a DE model is the shape of elements in the model. Currently circular shape (spherical in 3-D) is the common approach for the simulation of particulate bio-material. As the real shapes of these particles are mostly non-spherical, these models can not accurately represent the behaviour of a system comprising some real particles. In this paper a new model is introduced which can generate and simulate arbitrary non-spherical particles suitable for the simulation of fruits and vegetables which are not spherical. The results obtained from the analytical validation of the model showed 0.07% error which indicates that, formulas and the algorithms were well implemented in the model. The experimental validation of the model also showed that the model could predict the behavior of a physical system with 82% accuracy. Consideration of both the analytical and experimental validations of the model showed that on the whole the match between experiments and simulations were very good given the noise introduced by physical replication of the particle assembly and the variation in physical particle geometry and the hopper structure. To demonstrate the capability of the model some simulation examples have been presented. In these examples different particle shapes have been used in some systems typical of most agricultural system operations. The snapshots obtained from the simulations indicate that the Multi-sphere model can be a promising technique for the simulation of particulate bio-materials problems.