| Popis: |
The modern practice of using vibrating machines when working with small seeds of light weight is faced with such an undesirable phenomenon as the impact on the kinematics of vibrational motion of particles of fractions of the seed mixture of aerodynamic forces and moments. The results of the use of vibrating machines, which are the most effective means for the separation of fractions of fine-seed mixtures, are significantly deteriorating. Studies on the substantiation of the parameters of operating modes and structural improvements of vibrating machines in order to reduce or eliminate the action of the aerodynamic factor are becoming relevant. When using vibrating machines with packages of working surfaces for separation of small crops there is a harmful influence of an aerodynamic factor. In the space between the planes, there is a alternating movement of air, which reduces the efficiency of transmission to the seeds of the divided fractions of the pulses of vibrational motion. The quality of cleaning and sorting of seed material decreases. To assess the degree of influence of the factor of aerodynamic forces and moments on the degree of adequacy of the model, a double simulation of seed motion with pronounced aerodynamic properties was carried out: taking into account and without taking into account aerodynamics. Rational geometrical characteristics of the screen were established on the basis of the analysis of functional dependence of degree of decrease in harmful influence of an aerodynamic factor on the specified geometrical characteristics. The article proposes to solve this problem by equipping packages of working surfaces of the vibrating machine with special aerodynamic screens, which can significantly reduce the impact of harmful aerodynamic factors. According to the results of parametric research, an expedient design of the aerodynamic screen is proposed, which almost completely eliminates the harmful effects of the aerodynamic factor. The research was carried out on the basis of a numerical model of the motion of an ideal gas inside an oscillating flat channel when modifying the boundary conditions. |
