A discrete element approach for simulating the processing of fibrous biomass

Simulations are becoming increasingly important for the optimization of various processes. However, in the case of biomass processing the natural variability of the biological material adds an extra challenge. As the processing of crop stems is governed by the discrete interactions between the particles and the machine components, bulk models are inadequate to properly describe the crop-machine interaction for low and moderate particle densities. Discrete element modeling (DEM) has been proposed as a better way to model the behavior of particulate systems (Tijskens et al., 2003). Recently, its usefulness for simulating the flow of flexible stems has been demonstrated (Lenaerts et al., 2014). Leblicq et al. (2015) developed data based models which describe the buckling behavior of crop stems during bending and compression in DEM simulations. In this way, the decrease in deformation resistance with increasing damage was also taken into account. Using data based models, virtual bendable crop stems, with realistic geometries, could be created in the MPACTS software. Biological variability was introduced in the simulations by measuring different stems and using the corresponding calibrated deformation models. To do this in a correct and efficient manner multivariate statistical methods were applied. The virtual stems were used to simulate the compression of wheat straw in a compression box. The simulations were validated with bulk measurements. This calibrated DEM model can also be used to simulate the processing of crop stems by harvest and post-harvest machinery. REFERENCES [1] Leblicq, T., Vanmaercke, S., Ramon, H., & Saeys, W. (2015). Mechanical analysis of the bending behaviour of plant stems. Biosystems Engineering, 129, 87-99. [2] Leblicq, T., Vanmaercke, S., Ramon, H., & Saeys, W. (2016). A discrete element approach for modelling realistic deformable crop stems, unpublished. [3] Leblicq, T., Smeets, B., Vanmaercke, S., Ramon, H., & Saeys, W. (2016). A discrete element approach for modelling realistic deformable crop stems, unpublished. [4] Lenaerts, B., Aertsen, T., Tijskens, E., De Ketelaere, B., Ramon, H., De Baerdemaeker, J., et al. (2014). Simulation of grain-straw separation by discrete element modeling with bendable straw particles. Computers and Electronics in Agriculture, 24-33. [5] Tijskens, E., Ramon, H., & De Baerdemaeker, J. (2003). Discrete element modelling for process simulation in agriculture. Journal of sound and vibration, 493-514.status: publishe