Mechanical characterization of fibrous biomass for in silico forage harvester design

Livestock productions have played a crucial role in supplying human food, both in urban and rural communities. Therefore, among the numerous effective factors in animal husbandry practices, the quality of hay or silage, which are the most common fodder that animals consume, has a direct relation with the yield amount of production. In order to produce good quality hay/silage, it is important that the harvested crop is chopped into small particles. This process of harvesting and chopping of the fibrous biomass is done with a forage harvester. This agricultural machine cuts the crop (grass, corn,…), chops it and conveys the cut crop (forage) to a wagon/trailer for transport to the storage silo. The transport of the chopped crop from the cutter drum to the trailer is typically performed by utilizing pneumatic system. This system combines a centrifugal fan to produce an assisting high-speed air flow for accelerating the chopped crop particles in order to pass through the conveying channel. The speed and trajectory of the transported particles are the result of the complex interplay of the crop particles with the walls of the conveying tube and the assisting airflow. Large variation in the particle transport is observed in the field, regularly resulting in poor machine performance. It is hypothesized here that this variation in the material transport can be attributed to variation in the mechanical properties of the crop particles. The aim of this research is to investigate the impact of the variation in the mechanical properties of the crop particles on the material transport in a forage harvester. To this end, the dominant properties will be identified and measured for different crops, between different fields and within field. This increased insight in the interaction of the crop particles with the machine parts and air will allow to minimize the occurrence of stagnation and non-uniformity in the material transport, and to optimize the forage harvester design.