A mixing process is common in various industries for handling granular materials, with granulators widely used in pharmaceutical industry as prominent examples. In the context of geotechnics, a mixing process finds its application in various situations such as improving ground, producing concrete and a recent interest in mining and its potential usage for dredging [1]. In this study, we apply a high-performance-computing-based DEM code [2,3] to study the mechanical responses of a mixing process under water for mining and dredging. The simulation is calibrated by experiments on colored sand immersed in water. Torques and surface mixing patterns are compared in a quantitative fashion and a qualitative fashion, respectively. The influence from various geometrical and operational factors have been studied using numerical simulations. We focus on the influence on the torques on the mixer head and the forces on the ground and the container. The torque response is important for design while the force/pressure response can help to assess the risks, if any, accompanying the mixing process.

References

[1] Jian Chen, Mikito Furuichi and Daisuke Nishiura.  Discrete Element Simulation and Validation of a Mixing Process of Granular Materials. Materials, 2020, 13, 1208.

[2] Furuichi, M., Nishiura, D., Asai, M., and Hori, T., The first real-scale DEM simulation of a sand-box experiment using 2.4 billion particles. The International Conference for High Performance Computing, Networking, Storage and Analysis, Denver, CO, 2017.

[3] Nishiura, D., Sakaguchi H. and Yamanoto S., Multibillion particle DEM to simulate centrifuge model tests of geomaterials,   Proceedings of the 9th International Conference on Physical Modelling in Geotechnics 2018, volume 1, pp.227-232.