Discrete Element Modeling of Soil Displacement Resulting from Hoe Openers

Soil displacement is the most important performance indicator for seed openers, as it affects the uniformity of seeding depth. In this study, a hoe opener was modeled using Particle Flow Code in 3 Dimensions (PFC3D), a discrete element modeling software program. The objective was to simulate soil displacement in terms of soil throws. To validate the model, an air drill with hoe openers was tested in a field with clay soil at a working depth of 38 mm and travel speed of 8 km h-1. Soil throw resulting from the hoe opener was measured. To calibrate the model, a virtual soil shear test was created within PFC3D, and the output soil shear torque was compared to the torque measured in the same field. The result showed that the calibrated effective modulus, a critical micro-parameter of model particles, was 5.692 × 107 Pa. With this calibrated value, the simulated soil throws agreed well with the measured throws, with a relative error of 15%. The model was used to compare different hoe opener designs: single-shoot spread, double-shoot side-band, double-shoot paired-row, and triple-shoot openers. Among all these openers, the side-band opener resulted in the least lateral soil throw, and the paired-row opener resulted in the lowest vertical soil throw but the highest lateral throw. The developed model was effective for examining the effects of opener geometry on soil displacement. Keywords: DEM, Hoe, Opener, PFC3D, Soil displacement.