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EN
Efficient fuel injection and exhaust gas cleaning systems are needed to promote the development of high-performance internal combustion systems and decrease greenhouse gas emissions. Electronically controlled injection systems enable nearly unlimited control over system components whose operation is limited by the inertia of moving parts and other physical phenomena. In the present study, a novel technology for manufacturing magnetic cores was proposed to improve the performance of solenoid injectors in Diesel engines. The conducted simulations and experiments revealed that the developed technology can increase the speed of solenoid injectors. In the proposed solution, the fuel dose was split to effectively control the injection process and improve engine performance.
EN
This paper describes a method for finding the optimal parameters of a spark-ignition engine gas exchange system for a motorcycle. The vectors of the initial data for filling the parameter space, in which the search for the optimal solution has been made, have been formed through methods of experiment planning and technique nonlinear programming quadratic line search. As the quality criteria, the engine power has been used at selected points of the external speed characteristic. The results of the work have shown how using the proposed optimization method allows modernization of a gas exchange systems in order to increase the engine power.
EN
This paper presents a method for the precise diagnosis of a diesel engine in an agricultural tractor based on the analysis of efficiency changes and parameters characterizing the process of fuel-air mixture preparation. We proposed that the technical condition be identified based on available data from the engine controller, as this enables the implementation of precise online diagnostics of an agricultural tractor. The method was verified using the original cycle, during which we simulated several engine defects leading to a change in conditions and quality of the processes of creating and burning the fuel/air/flue gas mixture. In the paper, we justified the selection of the points at which the engine parameters were measured, as they provide the most information and allow for efficient identification of damage. These results indicate the possibility of damage identification without the use of the diagnostic cycle in the operation of operator-driven vehicles and autonomous vehicles.
EN
The article presents the results of tests, replaced according to the vehicle manufacturer's recommendations, of engine oils. The sample of engine oils in service came from spark-ignition and compression-ignition vehicles used in urban or mixed mode. During their collection, the type of drive unit, the mileage of the car and the number of kilometers the oil was used for were recorded for each sample (this was the main criterion for differentiating samples). In addition, a control group of samples consisting of fresh oils of the same viscosity grade and distributed by the same producer was set up to observe changes in the parameters of individual lubricants after the operating period. The first part of the empirical study consisted of determining the physico-chemical properties of the lubricants, i.e.: kinematic viscosity, density and water content. The second part involved anti-wear tests using a T-02U tribometer. The use of the tribometer made it possible to record the anti-wear parameter, i.e. moment of friction, and also the load imposed on the friction node, as a result of which it was possible to calculate the friction force and friction coefficient. The research was complemented by an analysis of worn surfaces of the friction node on a microscope. The tests carried out can be used for predictive purposes, in terms of assessing the condition of a lubricant subjected to an operating process in an internal combustion engine.
EN
This paper is concerned with the possibility of applying modern non-contact methods for assessing the wear as a result of tribological interaction between working bodies and the soil. An original method for wear testing using the test space discretization based on the 3D scanning technology was employed. A localized volumetric wear coefficient was proposed, allowing for wear analysis and improving the accuracy of the Holm-Archard model. The coefficient of local volumetric wear shows the influence of the nominal shape and the slip trajectory of the abrasive particle along the elementary surface on the intensity of wear. At local volumetric wear coefficient > 0.3, this factor determines the intensity of surface wear. Volumetric wear characteristics are the basis for prediction of wear consequences for different materials and techniques of reinforcement of working surfaces, subject to intensive wear in abrasive soil mass. The reliability of the study is confirmed by the comparison with the mass method for wear assessment and the results of the application of the proposed method for different conditions of abrasive wear of operating parts.
EN
The article demonstrates a rational scheme of the supercharging system in a helicopter diesel engine with a power of 100 kW, regardless of the flight altitude, and proposes a method for assessing the power losses for a diesel engine depending on the flight altitude using a mathematical model. There are three variants of an engine supercharger scheme with a single-stage turbocharger, a two-stage one with parallel or sequential compressor drive and a turbo-blower. As a result of the computational analysis according to the original method, it was shown that from the point of view of the least energy consumption two-stage scheme with a compressor and a sequential drive is the most rational. To reduce energy losses in the drive with two-stage supercharging, a concept for controlling the pressure system was proposed, which includes changing the rotational speed of the compressor drive and adjusting the throttles. Simulation of the engines running during the climb/descent of the helicopter showed that the proposed pressure scheme and control concept is effective. In order to improve the quality of regulation, the possibility to use an electric drive with the first stage compressor is being considered.
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