4/17/2023 0 Comments R studio anova![]() The transition between the horizontal seed distributor tube and the seed manifold in the implement is commonly achieved through horizontal-vertical elbows ( Figure 1a). The pneumatic conveyance systems found in air seeder designs vary by manufacturer but typically include a central seed storage tank with a seed metering mechanism, a series of horizontal distributor tubes that pneumatically convey seed from the storage tank to a seeding implement, and a seed manifold attached to the end of each distributor tube which further separates seeds into distinct rows for incorporation into the soil. Furthermore, research studies that examine particle impacts in horizontal-vertical elbow flow often focus on erosion rather than monitoring individual particle forces.Īir seeders have several features that work together to deliver a prescribed amount of seed into agricultural fields. ![]() However, there is limited data comparing one-way and two-way coupling for particles in the agricultural seed size range. One-way coupled CFD-DEM is not affected by the ratio of CFD element size to particle size and has been shown to perform well in simulations with small particles, such as sand. One-way CFD-DEM coupling includes the effect of fluid force (air) on particles (seeds), but the effect of particles on the fluid is assumed negligible. Considering solid loading ratios in air seeders are commonly within the dilute phase, there is an opportunity to use one-way coupled CFD-DEM simulations. The ratio of commonly used tubing size to agricultural seed diameters is not ideal for the requirements of the coarse-grid approach. Simulation results indicated that one-way coupling could be suitable to describe seed flow when two-way coupling may not be possible or practical.Īir seeder distributor heads normally consist of tubing with a horizontal-vertical 90-degree elbow transition that divides the flow of seed into multiple outlets at the end of the vertical tube section. Dimensional analysis revealed that seed contact force was proportional to the elbow diameter to the power of 0.26 and inversely proportional to the elbow bend radius to the power of 0.5. Overall, simulated seed velocities had a strong correlation to values calculated through the current pneumatic conveyance theory. Both methods resulted in nearly identical seed trajectory and force. Results showed that seed velocity was significantly different between one-way and two-way coupling. ![]() ![]() Simulated field peas ( Pisum sativum) were pneumatically conveyed to study the effect of air velocity (20, 25, and 30 m/s), seed rate (0.07, 0.21, and 0.42 kg/s), elbow diameter, D, (48.3, 60.3, and 72.4 mm), and elbow bend radius (1.5D, 2.5D, 3.5D, and 4.5D) on seed attributes (trajectory, velocity, and force). Additionally, simulated seed velocities were compared to the current pneumatic conveying theory for each coupling method. The performance of one-way and two-way CFD-DEM coupling methods was compared. A series of computational fluid dynamics–discrete element method (CFD-DEM) simulations were applied to seed flow in horizontal-vertical 90-degree elbows. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |