• Energy Research

The European Directive concerning pesticide sustainable use establishes regulations to reduce the environmental drift throughout treatments to agricultural crops, particularly in nearby sensitive areas, such as water bodies, natural reserves and urban areas. The drift represents the fraction of mixture delivered by the sprayer that is not caught by the crop, and is the clearest cause of environmental pollution. Anti-drift nozzles are usually employed, and buffer zones are also maintained along the edges of the sprayed field to reduce drift production. The aim of this work was the theoretical study of the motion of the spray droplets delivered by a nozzle, dipped in downwards and/or lateral forced air flows. A mathematical model has been developed, consisting of a system of 2nd order differential equations, to simulate the motion of water droplets of different diameters within simultaneous different directions of air flow. The graphs, obtained by means of the numerical solution of the model, allow us to analyze the level of the droplets’ drift, according to their diameter and to the speed of the lateral and the downward air flows, respectively. A lateral airflow at a speed of 5 m · s − 1 produced a drift in its direction until 1.70 m for droplets from 100 to 500 μm in diameter. For larger drops, the impact of the downward airflow is not very significant. The results obtained by the numerical solution of the mathematical model have been compared with the results of experimental tests carried out to evaluate the drift of spray produced by different nozzles.

Sustainability in the agricultural field suggests the conservation and maintenance of a natural environment of soil. Nevertheless, in the potato production chain, the mechanized harvest is carried out with the concurring removal of impurities and fertile soil. The authors have developed a new spiral potato cleaner which is able to capture and efficiently remove soil lumps of various sizes and shapes, as well as various plant residues. Theoretical and experimental studies have been performed on this soil clod cleaner to determine the structural and kinematic parameters that provide efficient capturing, motion and sifting down of the soil, through the gaps between the helices of its cleaning spirals. An analytical description of the motion of the clod of soil has been made and a system of differential equations has been compiled, whose numerical solution made it possible to determine the indicated reasonable operative parameters of the developed spiral potato cleaner. The results of the experimental research confirmed those ones obtained through the numerical solution of the mathematical model, i.e., rational angular speed ω of the rotation of the spirals from 20.0 to 30.0 rad s−1 and the radius R of spirals between 0.12 and 0.15 m.

The development of a mathematical model of a vibratory mill made it possible to determine the regularities for the complex movement of its operating mechanisms and obtain a graphic interpretation for the kinematic, power and energy characteristics of the vibratory system. On the basis of theoretical pre-requisites, a series of experimental studies were conducted that provided an opportunity to obtain the amplitude-frequency, velocity and energy characteristics of the machine under investigation and to determine their impact upon the kinetics of the fine grinding process of the grain. As a result, rational operating parameters of the examined machine were established with minimal energy input.

Abstract Due to the high energy intensity of lifting of deep-seated table root crops, their growth develops mainly in light sandy-loam soils, in which it is possible to transfer a heap of root crops to the separating devices in order to facilitate the qualitative separation. Therefore, issue of lifting of deep-seated table root crops at minimal energy consumption and labour costs is an important scientific and practical task, which would allow expansion of cultivation of deep-seated table root vegetables to heavy soils. Research was conducted by means of a theoretical method utilizing elements of theoretical mechanics with subsequent processing of results by means of PC. Mathematical model and resulting energy cost dependences were constructed on the basis of the device parameters for soil loosening and lifting of deep-seated table root crops. Refined mathematical model of the process of lifting of deep-seated root crops made it possible to find out scientific and technical preconditions for the development of lifting devices with minimal energy consumption.

Sugar beet is an extensive crop of great agronomic value with significant productive and economic returns and Ukraine’s sugar beet accounts for about 5.1% of the overall world production. Sugar beets and the by-products resulting from its manufacturing transformation are a significant renewable energy resource. A new high-quality performance prototype of a sugar beet top harvester, front mounted on a tractor, was built by the authors in Ukraine. The aim of this study is to evaluate the main performance parameters related to the operation of this new machine. Field tests were carried out linking the prototype to a wheel tractor, whilst suitable sensors measured the significant kinematic and dynamic parameters, allowing experimental data collection to assess the machine’s performance parameters. The entire technological process of harvesting and transporting the beet tops to the beet top storage unit required power ranging from 6.42 to 17.65 kW. At the topmost tested forward speed, the required tractor traction force was less than 1.9 kN with the power required by the shaft that drives the screw conveyor ranging from 3.1 to 4.6 kW. This value was the lowest for a speed of the tractor–beet top harvesting machine aggregate ranging from 0.9 to 1.2 m · s − 1 .