Multi-Visco-Elastic Contact Model in Discrete Element Method - Numerical Simulations of Margarine’s Dynamics during Manufacturing Process -

The multi-visco-elastic contact model embedded in the Discrete Element Method (DEM), which was developed by authors previous study (Shimizu et al., 2012) 1) is applied to simulations of margarine’s dynamics in a pin machine, in order to improve margarine’s uniformity during manufacturing process. The results are compared with those using the linear contact model. Also, parametric studies are conducted by changing the operational conditions. As a result, it was found that the new developed multi-visco-elastic contact model represents margarine’s dynamics well during manufacturing process. The following results are considered from the numerical simulations, that is, (1) the migration process is slower than that of granular material, which is often modeled by using the linear contact model in the DEM, also the loaded torque on the machine is around 30 % from the case of using the linear contact model, (2) the migration proceeds mainly in the circumferential direction rather than in the radial direction, as movement of the bulk in the circumferential direction is much larger than that in the radial one, (3) performance of migration in the circumferential direction improves by increasing rotational speed, which is not expected in the radial direction though. Further studies to examine load characteristics of the machine are needed to use the model as a design tool for improvement of the machine’s performance and development of new machines.