Analisys of a Seed's Pneumatic Dosage System. Comparison Between Laboratory Tests and Numerical Simulation Results

Abstract

In Argentina, soya (Glycine max L.) is the main extensive culture, with 19.000.000 ha of sown area and 54.384.926 tons of production (2009/10 growing season). The different soya species sown in a given zone need an adequate distance between each seed (dosagedistribution), in order to truly express its performance. In precision sowing, the more widespread dosage system is the monograin metering. At the present work, soya seed trajectories in a monograin metering system are studied. Comparison between laboratory tests and numerical simulation results are made. Tests consists on the seeds trajectory shooting, using a high speed video camera (420 frames per second), on a static sowing unit. This unit has a seeds hopper, a monograin dosage system air pressure assisted, and a seeds drop tube. Regarding to the numerical model, the mixing air-particles is considered as a dilute phase flow, where a one way coupling between each other is used. A Lagrangian approach is applied to particles, while an Eulerian approach is used for the fluid. The fluid is modeled with the Navier Stokes equations, using the Reynolds Average Navier-Stokes Standard (RANS) resolution technique, with a K – Epsilon turbulence model.