The Air Flow Distribution in the Overpressure Sowing Apparatus

Abstract

To improve the quality of the pneumatic sowing apparatus, it is necessary to study its aerodynamics. (Research purpose) Determination of air flow distribution in the upper part of the seed chamber of the sowing apparatus, taking into account the protrusions of the sowing disk, on which the quality of seeds dosing depends. (Materials and methods) The author chose a sowing apparatus operating at overpressure as an object of research. The author showed that the seed chamber constant sealing in it is provided by the protrusions of the sowing disk, which are made with cut edges on the side of the sowing disk metering element in two planes. The author applied computer simulation of the sowing apparatus. To conduct a numerical experiment, the initial and boundary conditions were determined, and the rotation of the seed disk was taken into account. The calculation of the model was carried out by changing the volumetric air flow in the range of 15-35 liters per second. (Results and discussion) The author constructed isolines of the air velocity distribution at various air flow rates. He determined the values of the air flow in the directions X, Y and Z in the sowing apparatus seed chamber. It was revealed that the largest and the smallest values of this indicator are achieved at 35 and 25 liters per second respectively. It was shown that at an air flow rate in the range of 15-25 liters per second, the distribution of the air flow in the upper part of the seed chamber would be optimal for transporting the seeds with a metering element. The air flow velocity components in Z direction vary in the range from 5.4 to 16.5 meters per second, and in the X and Y directions do not exceed 8 meters per second. (Conclusions) Based on simulation modeling, the author constructed and analyzed graphs of air flow velocity components changes in the three directions of air flow propagation. He determined the nature of the distribution of air flow in the excess seeds discharge area in the design of protrusions with cut corners. He proposed a rational range of air volumetric flow rate of 15-25 liters per second.