2012 Annual Report
The discrete element method (DEM) will be used to model adventitious grain commingling in bucket elevator legs. Existing particle models for corn, soybeans, and wheat will be used to create grain handling models in 3-d and quasi-2-d. The models will be applied to full-scale legs to evaluate the effect of: (1) operating parameters (flow rate, grain type, and cleanout procedures) and (2) design factors (uptake side, boot size, and cup design) on adventitious commingling levels. Preferred operating conditions and design characteristics for reducing undesirable commingling will then be evaluated.
A literature search showed that methodologies, such as photogrammetry, for vegetative barrier assessment are low-cost but provide a less accurate and two-dimensional assessment of tree porosity. Laser-based protocols for determining tree porosities are beneficial by providing complex parameters (especially three-dimensional representations) but are limited by equipment cost and training. Numerical simulations will be done and will be validated with field tests to determine optimal barrier characteristics.
Adventitious grain commingling in a pilot-scale bucket elevator boot system was simulated using three-dimensional (3-D) discrete-element method (DEM) models and validated with experimental data. Approximately ninety-three DEM models were evaluated by grain type, residual grains, boot size, particle generation and flow rate, and uptake side (i.e., front- or back-loading) to determine which DEM model best simulate the grain commingling. Appropriate validated particle models of corn and wheat kernels selected from simulated bulk grain property tests were used in the DEM boot models. The validated particle and boot models are being applied to full-scale boots to determine best management practices for predicting and reducing unwanted grain commingling.