Vol 14, No 3 (2020)

The paper considers the use of diesel-electric power plants on mobile vehicles, analyzes their use and application. Comparative power and mass characteristics of diesel and gas turbine power units are given; the positive and negative aspects of their use are shown. The efficiency of the introduction of gas turbine engines on tractors of various traction classes for agricultural purposes has been determined and a new kinematic diagram of the power plant of a mobile vehicle has been developed. An analysis was carried out and it was established that gas turbine agricultural equipment was never produced in Russia. There were carried out the individual experimental studies of not of a systemic nature, which were terminated for reasons independent of the result. The aim of the work is to develop an innovative kinematic diagram with an electric drive and a power unit based on a gas turbine engine for a mobile agricultural vehicle, using the latest advances in science and technology in terms of the development of gas turbine technologies. It has been established that the mass-energy characteristics of gas turbine plants are much better than diesel ones: the level of vibration is significantly lower, the torque of the power plant at low speeds is higher, the operation of the tractor is simpler. All these open up wide prospects for their use on mobile agricultural vehicles. Experimental studies on the processing of 1 hectare of area in terms of economic efficiency have shown the indisputable advantage of an almost laboratory model of a tractor with a gas turbine engine, relative to the same tractor with a diesel engine, which has been produced for many years, expressed, despite a slightly higher fuel consumption, in the use of cheaper kerosene.

The aggregates of advanced missile systems (AAMS) include autonomous launchers of a mobile ground missile complex, transport-and-installation, refueling, maintenance and auxiliary technical means of technological equipment, which must have operational, tactical and strategic mobility. Operationaland tactical mobility is understood as the ability of the AAMS to move from one point to another in a certain time. Strategic mobility is characterized by the adaptability of the AAMS to its loading and transporting by other types of transport, including rail, air, water. The average speed of movement is taken as a measure of mobility, which should be developed by AAMS in order to ensure the timeliness, efficiency and safety of performing the assigned tasks, as well as the possibility of getting out of the influence of the damaging factors of a nuclear explosion, primarily from excess pressure in the front of the shock blast wave. It is possible to increase the mobility of the AAMS by locating it on the basis of road trains, however, the existing designs of aggregates of road trains have disadvantages that reduce the flotation and, as a result, the average speed of movement, these include low support and geometric flotation. The geometric flotation is influenced by design factors. For example, an increase in overall width is typical for a road train, as the trailing link under the influence of lateral reactions of the supporting surface relative to the tractor track is shifted towards the instantaneous turning center. This displacement causes an increase in resistance to movement on deformable soils, and, consequently, a deterioration in flotation and a decrease in a number of other operational properties of the road train. It is possible to increase the mobility of the AAMS by placing them on the basis of a road train with an active trailed link, controlling the distribution of power flows supplied to the wheels of an all-wheel drive road train depending on the possibility of realizing free traction by each wheel, changing the position of the road train center of inflexions depending on the steering wheel angle and maneuver.

Cylinder liners made of gray cast iron are quite widespread in the design of engines of road construction vehicles. The negative properties of this structural material include relatively low strength and high fragility. This increases the probability of both manufacturing and operational defects. Therefore, improving the performance of the considered parts is an urgent problem. A promising direction in this case is the use of chemical-and-thermal treatment. The aim of the work is to study the effect of chemical-and-thermal treatment of gray cast iron on strength. The paper investigates the strength of cast iron subjected to chemical-and-thermal treatment (thermal diffusion surface alloying). On the basis of experimental studies, the effect of the thickness of the hardened layer on the strength was studied. A numerical model is created in the Ansys software. The effect of the hardened layer on the strength of cylinder liners of engines of road-building vehicles is investigated.

The article analyzes the existing methods for determining the driver's condition. Driving in a state of fatigue, according to various statistics, is the cause of a large number of road traffic accidents (RTA). The percentage of accidents in Russia associated with the driver falling asleep while driving in 2018 is about 20%, in the USA the number of accidents for the same reason reaches 100,000 per year. The aim of the work is to review existing approaches to recognizing driver fatigue and existing technical solutions in this area. The article discusses such approaches as fatigue recognition based on the physiological state of the driver, recognition based on the driver's behavior, namely his speech and visual signs while driving, fatigue determination based on the nature of the vehicle's movement on the road and based on the driver's actions on the controls, the approaches based on the subjective assessment of the driver's condition. The advantages and disadvantages of each of the approaches were analyzed. The paper also provides an overview of existing fatigue recognition systems from various manufacturers that are currently used on vehicles and are designed to warn the driver of impending fatigue. It was revealed that in modern conditions of road transport operation, the most optimal approaches to fatigue recognition are based on an assessment of the driver's impact on the steering wheel, visual signs of driver fatigue and the nature of the vehicle's movement on the road, therefore, it is proposed to further focus on these methods.

Modeling of wheeled vehicles is one of the main directions of development and practical application of software systems based on modeling the dynamics of body systems. In this paper, a technique for analyzing a vehicle tire by the finite element method under various types of loading is considered in order to identify the parameters of its simplified dynamic models. Based on the finite element method, a refined tire model is created. It takes into account the complex geometric shape of various tire parts, their material properties, as well as the contact interaction of the tire with the support. The efficiency of this model was tested, both when performing static calculations of the stress-strain state of the tire from the action of an external load, and when solving the generalized eigenvalue problem. The great influence of external load on the natural frequencies and vibration modes of the tire is confirmed. One of the possible applications of the considered method of finite element modeling of a tire is the performance of refined calculations of the dynamics of wheeled vehicles in the “Universal Mechanism” software package. There are several variants of dynamic tire models that can be used to study the dynamics of off-road wheeled vehicles, including a model based on the method of discrete elements and a model based on the method of coupled substructures. A model based on the method of discrete elements represents a number of absolutely solid bodies-particles, connected to each other and by a wheel disk by a set of elastic-dissipative elements. Each particle of this model has three linear degrees of freedom relative to the wheel disk. The results of calculations of the refined finite element model of the tire are necessary to identify the mass and elastic-dissipative properties of this dynamic tire model. In the model based on the method of connected substructures, the elastic displacements of the tire are represented as the sum of the admissible shapes of the elastic body. Static and natural vibration modes are used as permissible forms of an elastic body, calculated using a refined finite element model of the tire.

Nowadays, the world is actively developing alternative energy based on solar energy and wind energy. The reason for this is the obvious signs of global warming, probably caused by the emissions of greenhouse gases - products of combustion of fossil fuels. The production of electrical energy at solar and wind power plants, unlike traditional thermal power plants, does not lead to the emission of greenhouse gases into the atmosphere. This article examines the potential of wind power plants in the central zone of the European part of Russia, using the example of the Kaluga region. The open climatic data METAR of the meteorological station of the Kaluga International Aerodrome named after Konstantin E. Tsiolkovsky (KLF) was used when writing the paper. Authors used data on the average wind speed for three-hour intervals over one year. An analysis of the wind speed was carried out and a graph of the probability of observing one or another wind speed was built. The graph showed that the average wind speed in the Kaluga region is about 2 ... 4 m / s. The calculation of the generation of electrical energy by a serial low-power wind generator was made, the coefficient of utilization of the installed capacity of the ICUM = 7% was determined. It has been established that the Kaluga region has a low wind energy potential. It is possible to obtain electricity from wind in the Kaluga Region, but calculations shown that the payback period for such power plants under these conditions, even without taking into account the costs of installation, auxiliary equipment and maintenance of the wind generator, is about 30 years. As a result of the study, it was concluded that there is no economic feasibility of operating low-power wind power plants in the central zone of the European part of Russia.