Sirvi Autor "Bulgakov, Volodymyr" järgi

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The effect of a lateral airflow created on nozzle tip on the spray droplets deposition
(Estonian Academic Agricultural Society, 2021) Bulgakov, Volodymyr; Olt, Jüri; Pascuzzi, Simone; Gadzalo, Jaroslav; Ivanovs, Semjons; Adamchuk, Valerii; Panasyuk, Volodymyr; Ihnatiev, Yevhen; Estonian University of Life Sciences. Institute of Technology
Improved application efficacy of a plant protection products by using a pneumatic device to change the dispersion of spray droplets is depended on the intensity of crosswind. The laboratory investigations of the spraying process of plants by means of the nozzles of a pneumatic system determined the quality indicators of pressure in the injection process of 0.4 MPa – the droplet coating density of 19–46 pcs cm2 –1 for the weighted mean droplet diameters (WMD) in the other experimental variants was within 304–543 μm. These indicators were compared with those for the standard, anti-drift and air injection nozzle types in which the droplet coating density was 23–59 pcs cm2 –1 and the weighted mean droplet diameters (WMD) were in the range of 350 to 485 μm. An analytical dependence was obtained of the influence of the lateral airflow and air pressure in the pneumatic system upon the amount of the deposited spray liquid.
Experimental research into impact of kinematic and design parameters of a spiral potato separator on quality of plant residues and soil separation
(Estonian Academic Agricultural Society, 2020) Ruzhylo, Zinoviy; Bulgakov, Volodymyr; Adamchuk, Valerii; Bondarchuk, Anatoliy; Ihnatiev, Yevhen; Krutyakova, Valentyna; Olt, Jüri; Institute of Technology. Estonian University of Life Sciences
The experimental investigations carried out in field production conditions have proved that the process of cleaning potato tubers from extraneous material with the use of a spiral separator takes place due to the active conveyance of the heap by the turns of the cantilever mounted cleaning spiral springs. The cleaning spiral springs not only rotate at the set angular velocity, but simultaneously their cantilevered ends perform oscillatory motion, which arises due to the deflection of their longitudinal axes under the action of the weight of the potato heap fed into the work zone of the separator. The results obtained in the process of the field experiment investigations carried out by the authors have provided for obtaining the relations that enable selecting the optimum design and kinematic parameters of the spiral-type potato cleaning devices for the targeted separation rate and, accordingly, estimating their impact on the quality of the performed work process.
Experimental research into operation of potato harvester with rotary tool
(Estonian Academic Agricultural Society, 2021) Ihnatiev, Yevhen; Bulgakov, Volodymyr; Bonchik, Vitaliy; Ruzhylo, Zinoviy; Zaryshnyak, Anatoliy; Volskiy, Volodymyr; Melnik, Viktor; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The experimental research was carried out on a specially designed laboratory-and-field test unit with the use of a hydraulic vertical rotor drive and strain-gauge equipment mounted on a tractor as well as the set of interchangeable coupling pieces for setting the machine's operating duty. Research into the process of breaking two adjacent potato row beds with the vanes of a vertical rotor has been undertaken. A design and process schematic model has been proposed for the operation of the potato harvester. Experimental research into the geometrical parameters of the potato row has been carried out to select the design parameters of potato harvesters. Based on the results obtained during the experimental investigations, the rational ranges have been established for the work process of the rotary potato harvester, the methods of engineering clod breaking tools have been developed. Following the completion of the full factorial experiment, regression functions have been generated. Their analysis has proved that the following factors have the greatest impact on the optimisation parameters: the rotor diameter and the clearance between the rotor and the spherical discs. The following parameters have been optimised based on the response surface analysis: soil separation ratio S = 93.5%, tuber damage rate Pb = 0.97%, total power consumption by unit operation Nа = 18.27 kW, at the following pre-set values of the factors: nр = 77 min–1, Vm = 2.2 m∙s–1, dр = 0.825 m, l2 = 0.3 m. The maximum discrepancy between the results of the theoretical and experimental investigations for determining the design and process parameters of the potato harvester does not exceed 15%. The completed economic testing has proved the advantages of the experimental potato harvester as compared to the existing ones. That said, the separation ratio of the pilot machine is equal to S = 91.4%, which is 23% higher than in the reference case, while its tuber damage rate is equal to 1.14%, which is 5.0% better than in the reference case. The recommendations for the selection of the rational operation duty of the rotary potato harvester as well as the methods for the engineering analysis of the design and process parameters of clod breaking tools have been developed.
Research of a contact stresses in swivel elements of flexible shaft in screw conveyor for transportation of agricultural materials
(Estonian Academic Agricultural Society, 2022) Bulgakov, Volodymyr; Olt, Jüri; Ivanovs, Semjons; Trokhaniak, Oleksandra; Gadzalo, Jaroslav; Adamchuk, Valerii; Chernovol, Mykhailo; Pascuzzi, Simone; Santoro, Francesco; Arak, Margus; Estonian University of Life Sciences. Institute of Forestry and Engineering
The paper presents the new design of the rotating part with ball-bearing swivel joints between its sections for flexible screw conveyors. The new design provides for the improvement of the operation efficiency and loading capacity, the enhancement of the technological capabilities and the reduction of the admissible curvature radius. The contact stresses in the swivel element as the most loaded area in the rotating part have been analysed. It has been established that the maximum contact stresses arise at the points of contact between the ball and the flat surface of the slot in the cylindrical bushing. The recommended design limitation range for the cavity cone angle is within about 30–50. The relation between the loads and the stresses depending on the operating conditions has been modelled with the use of computer modelling. The comparison of the computer modelling results and the obtained calculation data has proved that the difference between the respective values varies within the range of 11–26%.
A study of the interaction between soil and the pneumatic wheels of agricultural gantry systems
(Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Olt, Jüri; Kuvachov, Volodymyr; Chernovol, Mykhailo; Sviren, Mykola; Kolomiiets, Serhii; Estonian University of Life Sciences. Institute of Technology
At the stage at which agricultural gantry systems are being designed, developed, and studied, the question of a rational choice of tyres for such systems is relevant, as tyres are the most important part of an agricultural gantry system and have a significant effect on most of its operating properties. The methods that can be used for choosing tyres for traditional mobile-powered equipment are already well established by scientific experience, but the movement of agricultural gantry systems in permanent artificial tracks creates somewhat different conditions and demands for a pneumatic tyre when compared to a traditional tractor moving along agricultural soil. This is why the development of methods that will assist in finding rational parameters for the pneumatic tyres of agricultural gantry systems that are moving along compacted soil in permanent artificial tracks is an urgent and relevant task. The purpose of the study is to optimise the parameters for the tyres of agricultural gantry systems in terms of their being able to travel on compacted soil in permanent artificial tracks. Theoretical studies and the synthesis of the parameters for a pneumatic wheel to work with an agricultural gantry system took place by modelling on a PC the performance conditions of such a vehicle. The basis for the study methods was formed by the fundamentals of tractor theory and theoretical mechanics, using the software program Mathcad. The traction factor of an agricultural gantry system's pneumatic wheel was used as the performance criterion for the effectiveness of the work being done by the wheel. The physical object of study was an agricultural system that has been developed by us. As a result of the study, it was determined that the solving of the task that has been set out - using an analysis of partial derivates of the function of the efficiency of an agricultural gantry system's wheel – makes it possible to quickly and effectively determine the rational optimum points for its pneumatic tyre's parameters. It was determined that, for the agricultural gantry system at hand, and in view of the maximum efficiency of its pneumatic wheel, the wheel's tyre width must be within the range of 0.20–0.30 m and its diameter must be within the range of 0.90–1.25 m. With those ranges, it is recommended that the tyre's inflation pressure be increased from 100 kPa to 160 kPa because the partial derivates of the function of the efficiency at those parameters would decrease to near zero. It has been proven that the choice of tyre type for agricultural gantry systems should be based first on the choice of its width and then its load-bearing capacity – its diameter. The proposed methods for finding rational parameters for pneumatic wheels make it possible to determine the tyre parameters for all kinds of agricultural gantry systems which will be required to travel on compacted soil in permanent artificial tracks. For the agricultural gantry system that has been developed by us, using tyres of the 9.5R32 type provides the highest levels of efficiency, i.e. at a factor of 0.86.
A theoretical and experimental study of combined agricultural gantry unit with a mineral fertiliser spreader
(Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Adamchuk, Valerii; Kuvachov, Volodymyr; Shymko, Lyubov; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
Operations to apply mineral fertilisers to the soil are an important part of practically every form of agricultural technology. The current global trend of transitioning to bridge and gantry-type agricultural systems leaves the unanswered relevant question of the effectiveness of the technological process of applying mineral fertilisers to the soil. This is relevant because, in gantry agriculture, a section of the arable soil is separated as an engineering area. This is why the main difference in gantry agriculture from traditional methods of the bulk spreading of fertiliser onto a field is that, with gantry systems, the amount of fertiliser that lands within the engineering zone are limited. This significantly affects the manufacturing costs involved in the entire area of agricultural technology and, as a result, the production costs of the end product. This study aimed to research the patterns that are apparent in affecting the parameters involved in the use of gantry-type equipment when applying fertiliser with the parameters and operational modes of a specially-developed electric spreader of mineral fertilisers. The physical object of the study was the agricultural gantry equipment that had been developed by the authors. This equipment, which is used for spreading fertiliser, was in the form of a tractor-mounted, suspended, single-disc spreader which was known as JarMet, and which had especially been modified to run from an electrical supply. The study indicated that the biggest influence on the speed of rotation of the centrifugal disc in the mineral fertiliser spreader stems from its height above the ground, the distance of track of the agricultural gantry itself, and the aerodynamic coefficient of the fertiliser. It was determined that, for the agricultural gantry with a distance of tracks of 3.5 m, a sufficient angular speed of the single-disc centrifugal tool is 15.5 rad·s−1, with a power demand for driving this at 0.35 kW·h. When using agricultural gantries of this type with an extended track width of up to 6 m, the necessary angular speed of the centrifugal tool for spreading fertiliser increases exponentially, to 318.2 rad·s−1, with the power demand for driving it increasing to the third power.
A theoretical and experimental study of the traction properties of agricultural gantry systems
(Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Olt, Jüri; Kuvachov, Volodymyr; Smolinsky, Stanislav; Estonian University of Life Sciences. Institute of Technology
The movement conditions experienced by an agricultural gantry system along the solid and level ground surface of permanent artificial tracks must make it possible to generate most of its maximum tractive force. Concurrently, the adhesive ability of the agricultural gantry system on the ground surface of such permanent artificial tracks must be sufficient to generate nominal drawbar pull when working at a certain level of slip. This means that there exists the need to seek out the following compromise: the maximum slippage experienced by the wheeled chassis of an agricultural gantry system must be such that, in a situation in which the level of adhesion with the surface of permanent artificial tracks is suitable, it will be able to generate the maximum possible tractive force. The effect of the parameters that involve an agricultural gantry system's wheels – and the physical and mechanical properties of the ground surface along which they move – on potential slippage has not yet been sufficiently studied. This effect cannot be taken into consideration without taking into account the dynamics of any rolling resistance being offered by the agricultural gantry system's chassis. The purpose of this particular study is to research the traction properties of an agricultural gantry system's wheeled chassis in terms of its movement along compacted and level ground upon which have been mounted permanent artificial tracks. The research determines that the wheels of such an agricultural gantry system that are rolling along permanent artificial tracks suffer less slippage and therefore generate a higher level of tractive force. As a result, the agricultural gantry system loses less of its speed of movement and, therefore, uses less energy in that movement. When an agricultural gantry system moves across an agricultural field that has been prepared for sowing, the research also determines the maximum tractive force that its wheels can develop when the adhesion coefficient is set at a figure that is between 0.22–0.24. Once such movement begins along permanent artificial tracks, this coefficient decreases to between 0.15–0.17. An agricultural gantry system's wheels are able to generate a higher level of tractive force when moving along on permanent artificial tracks. This figure is at least 30% higher when its movement has to be considered across an agricultural field that has been prepared for sowing.
Theoretical background for increasing grip properties of wheeled tractors based on their rational ballasting
(Estonian Academic Agricultural Society, 2019) Bulgakov, Volodymyr; Nadykto, Volodymyr; Kyurchev, Serhiy; Nesvidomin, Viktor; Ivanovs, Semjons; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The correct selection of the level of mechanical ballasting for wheeled tractors is among the most important issues for increasing their utilisation efficiency, in particular, increasing their grip properties. The shortcoming of the earlier undertaken investigations was that they virtually did not take into account the allowed maximum pressure of the tractor’s wheels on the soil. At the same time, little attention was paid to the impact of the maximum load-carrying capacity of the wheel tyres. The aim of the paper is to eliminate these deficiencies. Because of the authors’ efforts, the new technique has been developed, which differs in that it employs the requirement of the tyre’s ecofilic properties. The implementation of this requirement implies setting the maximum allowed level of the tractor wheels’ pressure on the soil and taking into account the maximum load-carrying capacity of the wheel tyres as well as the vertically applied load on each of the tractor’s axes under the simultaneous action of both the horizontal and vertical components of the tractive resistance of the employed agricultural implement. The practical effectiveness of the new approach is shown by the example of determining the possibility and level of ballasting the specific wheeled tractor operating as part of a ploughing unit.
Theory of Vibrating Lifting Tools of Sugar Beet Harvesters
(MDPI, 2022) Bulgakov, Volodymyr; Pascuzzi, Simone; Holovach, Ivan; Olt, Jüri; Adamchuk, Valerii; Santoro, Francesco
The cultivation and harvesting of sugar beets (roots and leaves) is one of the most labour and energy consuming work processes in the agricultural industry. The most important task in sugar beet farming is to improve the quality of sugar beet root crop harvesting and reduce energy costs for harvesting. This primarily concerns reductions in losses and damage of root crops, as well as a reduction in their contamination; in this case, the loss of fertile soil will be excluded, which will be removed from the fields together with the contaminated root crops. These issues present a multifaceted scientific and technical problem, which must be solved by searching for new working elements of sugar beet harvesting machines. Despite the modern level of construction of beet harvesters and their working bodies that has been achieved, there is a need to find further ways to improve them. Further research should deal with the improvement of general constructional schemes of new beet harvesters, with thorough theoretical justification of their constructions and technological parameters. The newly developed theories of functioning of improved constructions of sugar beet harvesters and their working bodies require thorough experimental verification. This will give grounds to use the obtained theoretical dependences for the final goal—analysis and generalisation of their rational parameters. Theoretical research must play a fundamental role in the mechanical and technological substantiation of the root lifting process. It must be used as the basis for developing rational kinematic and dynamic operation conditions in order to achieve the required quality of the performed work process as well as streamlined energy consumption. At the modern stage of the development of agricultural mechanisms, the methods of mathematical model generation based on the use of the theoretical and analytical mechanics and the application of up-to-date mathematical tools and computer technology have to be employed in the analysis and synthesis of the parameters of implements and agricultural machines overall. Thus, the modern methods of theoretical research into the implements of sugar beet harvesters have to be based, first, on the state-of-the-art perception of the principles of the processes that take place when the roots are lifted from the soil and, second, on the possibility of describing these processes more comprehensively and systematically with the use of modern mechanical and mathematical methods. Undoubtedly, such a description only has to be provided for the principal and essential moments of the mentioned processes, while the insignificant and incidental factors must be completely neglected. Further, on the basis of the analytically determined rational parameters of the lifting implements of sugar beet harvesters, which are subsequently experimentally validated and refined, highly reliable prototypes must be designed, which then have to be widely used by the agricultural engineering plants and companies. Therefore, this treatise presents the fundamentals of a new theory of the lifting tools of sugar beet harvesters—in particular, vibrational lifters based on the modern methods of mechanics and mathematics. It has been a long time since the first attempts were made (in the 1970s) to analytically describe the oscillating processes that take place during the vibrational lifting of sugar beet roots from the soil. The theory of the vibrational lifting of root crops has, overall, not been developed to a sufficient extent; the mathematical model specifically used for the process of root extraction from the soil by the vibrational lifter has not been devised. Until recently, it had been assumed that the experimental methods of determining the amplitude and frequency of oscillation of the vibrational faces—which could only have relatively limited values, subject to the reliability of the vibrational actuator—completely ensured the optimality of this whole process. However, at the present time, under the conditions of significant improvements in the reliability of designs and changes in the kinematic parameters of harvesting (for example, the increase in the travel speed to levels of up to 2.5 m·s−1 ), the obtained values of the parameters of vibrational lifters can by no means be considered optimal. Therefore, a goal has been set to develop, first of all, a new theory of vibrational root lifting based on the generation of mathematical models, which would describe the interaction between the digging shares on the one hand and the root’s body and the soil on the other hand. At the same time, the theory has to provide the mathematical descriptions of all stages of said interaction, starting from the stage of the lifter approaching the root body fixed in the soil (as in elastic medium), proceeding to the interaction of the root body with only one digging share of the lifter (asymmetric gripping of the root), followed by the interaction with both the share surfaces (symmetric gripping), and finally the eventual translation of the root along the lifting tool’s throat towards the level of the soil surface. Additionally, as a matter of principle, the theory needs to consider different (possible) directions of the oscillating motions of the digging shares of the vibrational attachment—i.e., the longitudinal and transverse ones.

Sirvi Autor "Bulgakov, Volodymyr" järgi

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