The chapter deals with a numerical simulation of a machine-tractor unit with an elastic-damping mechanism installed between an engine and a tractor transmission while fulfilling an agricultural performance (sowing). The mechanism is a complex system. The description of an elastic-damping mechanism shows all its advantages. There has been given a theoretical substantiation of a transparency level effect on a machine-tractor unit performance while sowing. The purpose of the work is to conduct theoretical study to identify the effect of an elastic-damping mechanism in a tractor transmission on working characteristics of a sowing machine. There has been obtained a regression equation and identified optimum parameters of an elastic-damping mechanism installed in a tractor transmission. There has been also given a substantiation of an expediency to install an elastic-damping mechanism in a tractor transmission for sowing grain crops.

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Sowing is one of the main operations in the technological complex of cultivation of cereals. Only with high quality seed distribution along the length and depth of the row can the maximum productivity and yield be achieved. A tractor with a seeding machine is subjected to continuously changing external influences that have a negative impact on the performance indicators of the technological operation. Based on the cereal cultivation technology, it is necessary to use tractors with transmissions that can absorb the oscillations and increase the stability of the coulter group of the seeding machine. Since this improves the quality of the operation, reduces the consumption of spent seed and fuel and increases environmental component of the process.

Rapid gravity flows of granular materials are a widely present type of rapid shear flows occurring in a large number of natural phenomena and engineering processes. However, to date, the parameters of rapid gravity flows have been hard to adequately describe because of experimental and analytical difficulties [1]. The investigation of rapid shear flows is within the scope of the mechanics of granular media. Rapid shear flows are often referred to as inertial flows since their properties are determined mainly by the inertia and mutual collisions of particles.Currently, there are quite a lot of mathematical models of rapid shear flows. They can be divided into two groups: (1) models formulated in terms of continuum theories, which are based on different forms of the relationship between the stress tensor and the strain rate and (2) models based on microstructural analysis, which evaluates stresses as functions of the momentum transfer by collisions of particles.Savage [2] proposed a mathematical model of the rapid gravity flow of particulate solids down a rough chute. This model is based on the Goodman-Cowin model, founded on the basic principles of continuum mechanics [3]. A serious drawback of these models [2, 3] is that they ignored the dependence of the properties of the flow on the boundary conditions at the flow surface.Later, taking into account the obvious disadvantages of the model formulated in terms of continuum theories, a number of researchers [4-7] developed rapid gravity flow models based on microstructural analysis. These researchers determined the stress tensor by analyzing the momentum transfer in interparticle interaction and solved a set of equations of conservation of energy and momentum of particles in their fluctuations and displacement. However, the assumptions made in these models led to errors, whose significance was shown by Hutter and Scheiwiller [1]. Hutter and Scheiwiller, using the Jenkins-Savage model [5], performed numerical simulation of the flow of a granular material down an inclined chute. They also established that the above models [4][5][6][7] require the adequate formulation of boundary conditions, which are difficult to define.Ackermann and Shen [6] carried out a geometric analysis of the microstructure of the shear flow and concluded that gravity flows are characterized by significant transverse mass transfer (quasi-diffusion) of particles. This should necessarily be taken into account in adequate simulation of flows. Moreover, in most of the available works devoted to analytically studying the fast shear gravity flows of granular media, it was assumed that the conditions of interaction of particles in a bed of a granular material are independent of the solid-phase concentration. This assumption significantly reduces the worth of these models. This was convincingly confirmed by Campbell and Brennen [8], who performed computer simulation of rapid shear flows of cohesionless inelastic rough particles and concluded that the effective friction coefficient (the ratio of the shea...

Only 30-40% of the plant productivity potential is realized in crop production technologies, which leads to a situation where the growth of field yields lags behind the growth of production costs. Increasing the realization of the productivity potential of cultivated plants is a way to improve the efficiency of the crop industry. The task of sowing machines is the uniform placement of seeds on the field area, while plants get their living space and, accordingly, form a crop. The practice of using such working bodies has shown that to achieve the necessary seeding regimes under the coulter elements, the use of additional sources of kinetic energy is required.