When separating (cleaning) lightweight seed mixtures with the help of vibratory machines, there is an issue related to the harmful effect of air movement in the gaps between parallel working surfaces of vibratory machine units. This factor is particularly harmful to seed material, which is sensitive to air movement (some medicinal and vegetable crops). To address this issue, the design of vibratory machines is changed while their operational regimes are configured accordingly. This requires many full-scale experiments and (or) time-consuming personal computer-based simulation of the working processes of the vibrational motion of such seed mixtures. This paper proposes several regression models that make it possible to replace time-consuming numerical modeling with simple analytical expressions (regression equations). These equations are used for a quantitative assessment of the degree of influence of aerodynamics on the kinematic parameters of the vibrational motion of particles of seed mixtures. The assessment is derived depending on the geometric characteristics of the aerodynamic screen, the design of the unit, and the amplitude of oscillations of the working surfaces of a vibratory machine. The models take the form of equations of multiple linear regression of the second order, obtained on the basis of a series of numerical experiments. The processes of vibration movement of the seed material of parsnips, lettuce, and fragrant dill were investigated. The coefficient of determination equaled 0,95 - 0,967. The results reported here are useful for the construction of algorithms to optimize the design and adjust the operating modes of vibratory separators according to the criterion of minimizing the harmful effects of the aerodynamic factor.

This paper reports results of studying the influence of geometrical parameters of the frame in a traction-transportation vehicle on its traction and energy indicators. A method for estimating the influence of geometrical parameters of the frame in a traction-transportation vehicle on its traction and energy indicators has been substantiated, based on the traction calculation of the tractor and taking into consideration the change in the distance from the hinge of the traction-transportation vehicle to the front and rear drive axles. The method makes it possible to determine the normal reactions, tangent thrust forces, and traction power on the wheels of the machine. The method reported here enables defining the optimal geometric parameters for improving the traction-adhesion and fuel-economic indicators of the traction-transportation vehicle. It was theoretically established that the normal reactions on the front wheels of the studied traction-transportation vehicle are 27,800 N and exceed by 1,95 times the normal reactions on the rear wheels of 14,200 N. This is due to the fact that the distance from the hinge to the corresponding axles of the wheels is 1,89 m and 0,97 m. Increasing the distance from the hinge to the axle of the rear wheels to 1,17 m produces a positive effect on improving the tractive performance of the traction-transportation vehicle. There is an increase in the tractive power on rear wheels to 24,39 kW. The experimental study of the traction-transportation vehicle was performed using an all-wheel-drive machine with a hinge-connected frame as an example. The maximum traction power is 121 kW, which is achieved at a speed of 12 km/h, traction efficiency of 0,68, and a thrust force per hook of 30,2 kN. The difference between the results obtained theoretically and experimentally is 8 %. Applying the method could make it possible to provide designers and manufacturers with recommendations for the construction and improvement of a traction-transportation vehicle, to improve traction and adhesion properties, and reduce the anthropogenic impact on the soil.

To reduce the complexity of research into designing promising vibratory machines while minimizing the harmful effect of the aerodynamic factor, it is convenient to use regression models. With their help, a quantitative assessment of the effectiveness of separation (cleaning) of seed mixtures is carried out, depending on the design parameters and the mode of operation of vibratory machines. This paper reports the results of research on the construction of regression models for parsnip seeds based on numerical modeling and full-scale experiment. Based on numerical modeling, a four-factor regression model of the second order was built, which takes into account the geometric characteristics of the aerodynamic screen, the design of the set of working surfaces, and the oscillation amplitude of a vibratory machine. Based on a full-scale experiment, a three-factor regression model of the second order was constructed for a constant gap between the working surfaces. A comparative analysis of the resulting regression models suggests that numerical modeling provides satisfactory accuracy in assessing the influence of the aerodynamic factor. This estimate, when using a regression model based on a numerical experiment, exaggerates the estimate determined by the full-scale experiment by 5 - 15 % (depending on the regressate variation area localization). Hence, the numerical model of the process of vibrational motion of light-weight seeds, taking into account the action of aerodynamic forces and moments, used to build a regression model of separation of parsnip seeds, can be considered adequate. Regression models (for parsnips and other plant crops), which are built on the basis of numerical modeling, should be used to solve problems of optimizing the parameters of vibratory machines according to the criterion of reducing the harmful effect of the aerodynamic factor.