Wyniki wyszukiwania - BazTech

1

Study on the relationship between vehicle maintenance and fuel consumption

Sakno Olha, Medvediev Ievgen, Kolesnikova Tatiana

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 113

163--172

EN

A contemporary road vehicle (RV) is a rather complex system, consisting of a large number of subsystems, assemblies, units, and elements (parts). While operating, an RV interacts with the environment, and its elements interact with each other. Consequently, the properties (parameters) of these elements change in the process - hardness, roughness, size, relative position, gapping, etc. A partial solution to the presented problems can be the search for a technique for assessing the RV technical condition by a generalised criterion, which is quite sensitive to changes in the technical state. One of these criteria may be fuel consumption in litres per 100 kilometres. This paper investigates the possibilities of using the fuel consumption indicator as a criterion for assessing the technical condition of the vehicle and the vehicle maintenance and repair technologies have been generalised to obtain a given technical solution. Thus, the possibility of using the fuel consumption indicator as a criterion for assessing the technical condition of the vehicles was explored using the Volkswagen Touran 1.9 TDI operating in urban conditions using a driving cycle. A clear correlation between the fuel consumption and the service lifetime of the vehicle has been established; therefore, it depends on the frequency and quality of the maintenance and repair (MR). The vehicle MR technology has been generalised to obtain a specified technical solution. The process of creating an RV MR Technology model is implemented based on an iterative approach (repetition) with the possibility to specify their features.

2

Fabrication and characterization of Zr microplasma sprayed coatings for medical applications

Voinarovych Sergii G., Alontseva Darya L., Kyslytsia Oleksandr N., Kaliuzhnyi Sergii, Khozhanov Alexandr R., Krasavin Alexander, Kolesnikova Tatiana

Advances in Materials Science

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2021

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Vol. 21, nr 2(68)

93--105

EN

This paper presents new results of studying the influence of parameters of microplasma spraying (MPS) of Zr wire on the structure of Zr coatings. The coating experiments were accomplished in a two level fractional factorial design. Individual particles of sprayed Zr wire and their splats on the substrate were collected under various spraying parameters (amperage, spraying distance, plasma gas flow rate and wire flow rate) and evaluated by Scanning Electron Microscopy (SEM) to establish the effect of particle size and shape on the coating microstructure. The particles were characterized by measurement of their sizes and the obtained results were evaluated in terms of their degree of melting. This was compared with the experimentally observed coating microstructure type and finally correlated to the investigated coating porosity to select the specific MPS parameters of Zr coatings depositing onto medical implants from Ti alloy. It was found that the main parameters influencing the size of the sprayed Zr particles and the porosity of the Zr coatings are the plasma gas flow rate and amperage. It was demonstrated that it is possible to control the porosity of Zr microplasma coatings in the range from 2.8% to 20.3% by changing the parameters of the MPS. The parameters of microplasma spraying of Zr wire were established to obtain medical implant coatings with porosity up to 20.3% and pore size up to 300 μm.

3

Theoretical research response time of the mechanism for compression ratio changing of the conrod-free engine

Kolesnikova Tatiana, Mischenko Nikolay, Sakno Olha, Suprun Volodymyr, Filipova Galynaa, Nikitchenko Igor, Gorpyniuk Andrii, Nazarenko Mykola

Zeszyty Naukowe. Transport / Politechnika Śląska

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2019

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z. 104

69--83

EN

The mathematical model for calculating the response time of the compression ratio of the mechanism for compression ratio changing (MCRC) is presented in this article. This revealed the influence of various engine factors with the connecting rod and crank mechanism (CRCM) on the operation of the MCRC (for example, the rate of the compression ratio change). The results of the study of the operation of the MCRC indicate a strong influence of the values  (relative area of flow passage of channels) and р (pressure) on the response time τ in the field of their small values. This indicates that with insignificant changes of the area of flow passage of channel of the hydraulic lock and the minute oil pressure in the cavities, a significant response rate of the MCRC is ensured. The results demonstrate the possibility of speedy compression ratio change in the engine with the MCRC. Calculation studies showed that the mechanism full operation occurs quickly (0.02 s per unit εx), which indicates the expediency of using such a high-pressure pump in a four-stroke gasoline engine with CRCM. The mechanism movable body complete movement (S = 4 mm) at the oil temperature in the hydraulic system of 45°C and pressure on the body of p = 60 bar are stated to occur for 0.2 s.

4

Impact evaluation of piston rings mobility on a gas passage in an internal combustion engine (ICE)

Zarenbin Volodymyr, Kolesnikova Tatiana, Sakno Olha, Ollo Vasyl, Klimenko Victor

Zeszyty Naukowe. Transport / Politechnika Śląska

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2019

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z. 104

187--201

EN

To estimate the effect of the axial movement of piston rings in the piston grooves on the blow-by in the internal combustion engine (ICE) by an experiment- calculated method. This contributes to the development of practical recommendations for the further improvement of the engine ring seal designs. Abstract theorems were used when modelling the effect of the axial movement of piston rings in the piston grooves on the blow-by in an ICE. They are based on the fundamental theory of heat engines, thermodynamics and hydraulics. The ICE running was analysed using design-theoretical research methods. The effect of the axial movement of piston rings in the piston grooves on the blow-by in the ICE was established. This creates prerequisites for a more accurate assessment of their sealing capacity and for ways to further improve them. Calculated dependences for computing the blow-by depending on the positional relationship of the rings in the piston grooves were obtained. The dependences of gas escapes on the engine crankshaft speed were obtained, which is especially important for idling modes by which one can judge the dynamic stability of the ring seal and solve the problems of improving its service properties. The calculated dependences for evaluation of the blow-by depending on the positional relationship of the rings in the piston grooves and their respective possible gas flows in the ring seal were obtained for the first time. The practical method for estimating the dynamic stability of the ring seal by decencies of gas escape on the crankshaft rotation speed in ICE was proposed.