Theoretical studies of fluid motion in the tank hydropneumatic sowing device

Abstract

In a known hydraulic distributor mechanisms, the process of forming fluidized layer is provided by mechanical means, the mixing of the considerable volumes of liquid with the seeds, resulting in higher energy consumption for the drive of the mixing device. The contact of the seeds with the working elements of the agitators causes the injury of germinated seeds. The hydropneumatic device coordinate device allows to eliminate these drawbacks by use of hydraulic fluidization method of forming a layer of a given concentration of seeds. As a result of the conducted research, built a mathematical model of fluid motion in the tank hydropneumatic sowing device using the software package STAR-CCM+, which is implemented by finite element method. We used an adaptive regular grid with variable cell size. As the model generator of the prismatic layer grid, the generator of polyhedral cells and the surface mesh generator. At the first stage of numerical experiment it was determined the vector velocity field of the fluid at different positions of the outlet capacity hydropneumatic sowing device. The second stage of numerical simulation was carried out by full factorial experience with the total number of experiments is – 32 = 9. As a result of modeling were obtained the velocity distribution of the liquid in the intake chamber depending on the angle between the surfaces of the suction chamber and the velocity at its input. The analysis of the research proves that with the gradual expansion of the suction chamber is closer to the border occurs a negative value of the projection of the velocity on the vertical axis – this indicates the presence of turbulent flow associated with the resistance of the liquid, which creates the wall of the suction chamber. Subject to slight variations in the density of seeds and the working fluid can be assumed that seeds in the fluidized bed will move along the streamlines of the fluid to rise from the center and down the walls of the chamber. Conducted research in a laboratory setting hydropneumatic sowing device, prove the adequacy of the obtained mathematical model of fluid motion.