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EN
The exhaust valve seat face is a surface that degrades slowly as a result of mechanical and thermal stresses. There is extensive research on new materials for valves and for the improvement of valve production technology. This paper discusses the method of obtaining a filler metal made of Fe3Al intermetallic phase and the method of TIG hard-facing on a valve seating face made of H9S2 steel, evaluating the effects of essential hard-facing parameters. The resulting hard-facing build up was assessed in terms of quality using industrial radiography testing (RT).
EN
Due to the growing awareness of ecological threats, more and more attention is paid to the emission problem of undesirable substances into the atmosphere, the source of which is transport and energy. The impact of these factors on the environment can be reduced by using alternative fuels, which are non-fossil fuels, or by modifying these fuels to ensure lower emissions. One of the methods for reducing emissions from engines is the use of water fuel emulsion as fuel, which has a particularly positive effect on the emission of nitrogen oxides at high loads of drive and power units. An important issue affecting the possibility of using this fuel type is the impact of their use on the elements of the units in contact with fuel containing water and, optionally, an emulsifier. This paper presents inspection results of the hot section of a miniature gas turbine powered by Jet-A1 aviation fuel with the emulsifier addition. On the basis of these observations, the components of emulsion fuels were determined, which are the cause of the characteristic deposits occurring on the hot sections of the units after using emulsion fuels.
PL
Ze względu na rosnącą świadomość zagrożeń ekologicznych przykłada się coraz większą wagę do problemu emisji do atmosfery substancji niepożądanych, których źródłem jest transport i energetyka. Jedną z dróg prowadzących do zmniejszenia wpływu tych czynników na środowisko jest wykorzystanie paliw alternatywnych, będących paliwami niekopalnymi, bądź modyfikacja tych paliw zapewniająca mniejszą emisję. Jedną z metod obniżenia emisji z silników jest zastosowanie, jako paliwa, emulsji paliwowo-wodnej, która wpływa szczególnie pozytywnie na emisję tlenków azotu przy dużych obciążeniach jednostek napędowych i energetycznych. Ważną kwestią wpływającą na możliwość zastosowania tego typu paliw jest wpływ ich stosowania na elementy jednostek będące w kontakcie z paliwem zawierającym wodę oraz opcjonalnie emulgator. W niniejszej pracy zostały przedstawione wyniki inspekcji gorącej sekcji miniaturowej turbiny gazowej, która była zasilana paliwem lotniczym Jet-A1 z dodatkiem emulgatora. Na podstawie tych obserwacji określono składniki paliw emulsyjnych będących przyczyną występowania charakterystycznych osadów występujących na gorących sekcjach jednostek po zastosowaniu paliw emulsyjnych.
EN
Future options for addressing the depletion of fossil fuels and reducing pollution from internal combustion engines may include biofuel as an alternative fuel. This study aims to experimentally and statistically assess the effect of using diesel-biofuel blends on the emissions of a single-cylinder direct-injection engine. Using recycled olive oil, a chemical Tran’s esterification process was used to create biofuel. The experimental results were contrasted with those of a one-dimensional engine model for exhaust emissions and torque, which showed high agreement between test and numerical data. In order to comprehend the factors that affect the engine’s reaction to variations in fuel composition, the thermodynamic characteristics of the engine for various blends were also supplied. According to the investigation, a mixture with 20% of the volume fraction of oleic acid methyl ester olive-based biofuel and 80% of the volume fraction of pure diesel can be an effective fuel alternative for cleaner exhaust emissions while offering almost the same performance.
EN
The study discusses the issues of low durability of dies used in the first operation of producing a valve type forging from high nickel steel assigned for the application in motor truck engines. The analyzed process of manufacturing the exhaust valve forgings is realized in the coextrusion technology, followed by forging in closed dies. This process is difficult to master, mainly due to elevated adhesion of the charge material (high nickel steel - NCF3015) to the tool substrate as well as very high abrasive wear of the tool, most probably caused by the dissolution of hard carbide precipitates during the charge heating. A big temperature scatter of the charge during the heating and its short presence in the inductor prevents microstructure homogenization of the bearing roller and dissolution of hard precipitates. In effect, this causes an increase of the forging force and the pressures in the contact, which, in extreme cases, is the cause of the blocking of the forging already at the beginning of the process. In order to analyze this issue, complex investigations were conducted, which included: numerical modelling, dilatometric tests and hardness measurements. The microstructure examinations after the heating process pointed to lack of structure repeatability; the dilatometric tests determined the phase transformations, and the FEM results enabled an analysis of the process for different charge hardness values. On the basis of the conducted analyzes, it was found that the batch material heating process was not repeatable, because the collected samples showed a different amount of dissolved carbides in the microstructure, which translated into different hardnesses (from over 300 HV to 192 HV). Also, the results of numerical modeling showed that lower charge temperature translates into greater forces (by about 100 kN) and normal stresses (1000 MPa for the nominal process and 1500 MPa for a harder charge) and equivalent stresses in the tools (respectively: 1300 MPa and over 1800 MPa), as well as abrasive wear (3000 MPa mm; 4500 MPa mm). The obtained results determined the directions of further studies aiming at improvement of the production process and thus increase of tool durability.
EN
The aim of the research was to analyse the possibility of using neural networks to determine the parameters of the chemical composition of exhaust gases as a function of engine performance parameters obtained from the on-board diagnostics system such as crankshaft speed and engine load index. The subject of the study was a Fiat Panda car equipped with a 1.3 Multijet diesel engine and powered by pure diesel. The tests used the MAHA MET 6.3 exhaust gas analyser and the on-board diagnostics system OBD II. The obtained values of NOx,O2,CO2 and PM measured behind the DPF were analysed. For the purpose of building a neural network model, preliminary studies were carried out in non-urban traffic (high-speed route). Based on the data obtained, processes of learning neural network structures with approximate properties with backward propagation of errors were carried out. Subsequently, tests were carried out on the operational parameters of the vehicle and the chemical composition of exhaust gases in urban traffic. Analysis of the obtained values of the average parameters obtained during the measurement and obtained on the basis of the prepared neural models allows to determine the relative differences at the level of not more than 10 percent.
PL
Czy małe statki mogą być zasilane ekologicznym paliwem gazowym? W szczecińskiej stoczni powstaje pionierska jednostka, w której jako źródło napędu zastosowano skroplony gaz (LNG). Statek Magda I jest świetnym przykładem dla armatorów małych jednostek, iż można pokusić się o zmianę oleju napędowego na paliwo gazowe. Ma to ogromne znaczenie dla ochrony środowiska.
EN
The engine intake pipe is an important part of the engine. A reasonable layout of the intake pipe can prolong service life of the engine and improve engine power. The optimization of design of the intake pipe has a great impact on the overall performance of the engine. The design of the intake pipe based on experience is subjective and unilateral, and the design cycle and experimental period are long. Ansys Fluent software is used to simulate the design, which can more intuitively reflect the air flow condition of the intake pipe and enable selection of the best layout. First of all, a three-dimensional model of the intake pipe is simulated and the airflow characteristics are studied and analyzed. The streamline diagram and velocity contour under various conditions are obtained. Then, compared with the simulation results, the position of the intake pipe is optimized. Finally, the optimized intake pipe is simulated and verified. According to the experimental results, the intake performance of the optimized intake pipe is greatly improved.
PL
W opracowaniu przedstawiono sposób przeprowadzenia oszacowania wartości wtrącenia reaktywnego tłumika akustycznego zainstalowanego na wylocie silnika spalinowego, na podstawie pomiarów laboratoryjnych wykonanych w odmiennych warunkach termicznych i przepływowych od występujących w układach rzeczywistych, w jakich te tłumiki zostały zamontowane.
EN
The article discusses the innovative concept of the over-expanded thermodynamic cycle, the author of which is the Polish engineer-designer Mirosław Szymkowiak. This cycle is realized on the basis of a new and innovative, previously unknown design, of a piston-crankshaft linkage mechanism with the aid of an additional element known as a rocker arm. Additionally, the proposed mechanism allows for a smooth change of the compression/expansion ratio of the engine during its operation. In the beginning, the earlier conceptions of the rocker engine developed by Szymkowiak were presented, and then the main construction assumptions and kinematic calculations were described. It was confirmed, that the developed linkage has big potential in improving the engine's thermal efficiency by approximately 12% relative. Additionally, it significantly reduces the exhaust gas pressure, when the exhaust valve is opened, therefore, contributes to the reduction of the noise emitted by the engine.
EN
This article considers the main materials used to make aircraft, both fuselage and engines. First, the problems that force developers to introduce new materials in aircraft production are identified. We then present features of the introduction of heat-resistant titanium alloys, ways of improving the mechanical properties of parts made of titanium alloys, and methods of manufacturing complex details. Other promising materials for the aviation industry, such as high-entropy alloys, quasicrystals, carbon-carbon materials, and nickel foam, are also considered.
PL
W artykule rozważono główne materiały stosowane w budowie samolotów, zarówno w kadłubach jak w silnikach. Najpierw uwagę zwrócono na problemy, które skłaniają konstruktorów do wprowadzania nowych materiałów do produkcji samolotów. Następnie przedstawiono charakterystykę wprowadzania żaroodpornych stopów tytanu, sposoby poprawy własności mechanicznych części wykonanych ze stopów tytanu oraz metody wytwarzania złożonych detali. Rozważono również inne materiały perspektywiczne dla przemysłu lotniczego, takie jak stopy o wysokiej entropii, kwazikryształy, materiały typu węgiel/węgiel oraz pianki niklowe.
EN
Climate change, environmental degradation and the introduction of increasingly restrictive legal regulations mean that the automotive industry is facing tremendous challenges. The paper presents a computer tool that uses the results of tests carried out on a chassis dynamometer for a Fiat Panda 1.3 Multijet, to simulate driving tests. As a result of the work of a computer tool, the impact on CO2 emissions was analysed in the context of CADC - Artemis (Common Artemis Driving Cycles) road tests for the following fuels: diesel oil, FAME (Fatty Acid Methyl Esters), rapeseed oil and butanol. Mass consumption of fuels and CO2 emissions were analysed in driving tests for the vehicle in question. The highest mass consumption of fuel and carbon dioxide emissions occurred in the case of FAME (respectively 2.283 kg and 6.524 kg).
PL
Oszacowanie wyważenia zespołu pomp żerdziowych bez żurawia na podstawie wartości zużywanego prądu
EN
The article presents an engineering approach that allows us to collect engine operation characteristics using built-in telemetry mechanisms, filled with the passive recording system. As a result of the development of the solution, the characteristics of the engine operation were obtained under real conditions, and the universal registration tool was built with a wider application than simply the registration of the engine operating parameters. The development of the solution allowed measurements to be obtained in a passive mode using a distributed architecture for engine monitoring and engine operation characteristics, which would be difficult to obtain and archive without logger production, especially during flight tests.
PL
W artykule przedstawiono podejście polegające na dostosowaniu pasywnego systemu rejestracji pracy silnika do systemu telemetrycznego silnika w taki sposób, aby był dla niego niewykrywalny. Jest to podejście inżynierskie, które pozwoliło na zebranie charakterystyk pracy silnika w warunkach rzeczywistych. Zbudowano uniwersalne narzędzie rejestrujące o szerszym zastosowaniu niż rejestracja parametrów pracy silnika. Opracowanie rozwiązania umożliwiło uzyskiwanie pomiarów i monitorowanie silnika w trybie pasywnym z wykorzystaniem rozproszonej architektury, które bez produkcji rejestratora byłyby trudne do uzyskania i zarchiwizowania, zwłaszcza podczas prób w locie.
14
EN
The aim of this study was to examine the relationship between the occurrence of selected types of failures and the time and season of their occurrence in public transport buses in the city of Lublin. The analysis was carried out for buses operated in the Municipal Transport Company within the past 3 years. The chi-squared analysis showed that during operation, there are significant differences between the failures and the annual season, but there are no differences between the frequency of failures and the time of day.
EN
This paper presents a comparison of two approval tests for a passenger car, both the current procedure and its predecessor. The car that was the subject of the study received a roadworthiness certificate based on the NEDC test, however, the emission results were compared with the new test procedure. The analysis showed the significance of the "start-stop" system in the conducted tests, however, assuming the original equipment of the car (active "start-stop" system), the WLTP test showed higher CO2 emissions, which did not exceed the permissible emission standard for this model specified in the relevant regulation.
PL
Niniejsza praca przedstawia porównanie dwóch testów homologacyjnych dla samochodu osobowego, zarówno aktualnie obowiązującą procedurę jak i jej poprzednika. Samochód, który był obiektem badań, świadectwo dopuszczenia do ruchu otrzymał na podstawie testu NEDC, jednakże porównano wyniki emisji z nową procedurą testową. Dokonana analiza wykazała istotność systemu „start-stop” w przeprowadzonych badaniach, zakładając jednak oryginalne wyposażenie auta (aktywny układ start-stop) test WLTP wykazał wyższą emisję CO2, jednakże nie przekroczyła ona dopuszczalnej dla tego modelu normy emisyjności określonej w stosownych przepisach.
PL
Przeprowadzono testy symulacyjne dla oleju napędowego (ON) i estrów metylowych kwasów tłuszczowych otrzymanych ze zużytego oleju kuchennego. Podstawą obliczeń był proces termicznego tworzenia się NO zgodnie z mechanizmem Zeldowicza dla silników Diesla. Współczynniki szybkości reakcji wyznaczono metodami Baulcha, GRI-MECH 3.0 i Heywooda. Stężenie NO obliczone metodą GRI-MECH było najbliższe wynikom doświadczalnym. Metoda ta może znaleźć potencjalne zastosowanie do szacowania rzeczywistych stężeń NO powstającego w silniku spalinowym napędzanym paliwem alternatywnym i innymi paliwami wyższej generacji o podobnych właściwościach fizykochemicznych.
EN
Simulation tests were carried out for diesel oil (ON) and fatty acid Me esters obtained from used cooking oil. The calcs. were based on thermal NO formation according to the Zeldovich mechanism for diesel engines. Reaction rate coeffs. detd. by Baulch, GRI-MECH 3.0 (G) and Heywood were used. The NO concn. calcd. by method (G) was closest to the results of the exptl. detd. NO concn. and was the best method to demonstrate the actual NO concs. formed in an internal combustion engine fueled with alternative fuel and other higher generations fuels with similar phys. and chem. properties.
17
Content available remote Diagnozowanie jakości powierzchni tłoka aluminiowego po procesie fosforanowania
PL
We współczesnych przedsiębiorstwach kontrola jakości prowadzona po procesach obróbki chemicznej, jako procesach specjalnych, stanowi jeden z kluczowych elementów ukazujących poziom organizacji produkcji. Umiejętne stosowanie dostępnych technologii oraz dostępnych instrumentów zarządzania jakością stwarza możliwość ciągłego eliminowania niezgodności u ich źródeł. Celem badań było zdiagnozowanie powierzchni tłoków poddanych przemysłowej obróbce powierzchni poprzez fosforanowanie. Tłoki te przeznaczone były do silników diesla stosowanych w pojazdach lekkich. Określono źródła niezgodności powstające w procesie fosforanowania odlewów. Wykorzystano w tym celu i zintegrowano wybrane techniki zarządzania jakością. Działania te przyczyniły się do znacznego zmniejszenia liczby wyrobów niezgodnych.
EN
The Ishikawa diagram and ABCD-Suzuki method were used to det. the reasons for incorrect coverage of the Al piston surface with a phosphate layer. The defect resulted from inadequate degreasing of the piston surface.
EN
Users of fossil fuels are facing a range of challenges such aslong-term rising demand, climate concerns due to emission ofgreenhouse gases, ecological pollution, finite reserves and price fluctuations. Diesel fuel is similarly affected, though with its own subset of issues. Studies suggest that diesel fuel characteristics are affected by addition of nanoparticles. In this research, carbon nanotubes (CNTs) were blended with pure diesel as an additive at concentrations of 30, 60, and 90 ppm to assess the emission and performance characteristics of a single-cylinder compression combustion engine. The considered emission contents included CO, CO2, HC, and NO produced by an engine at 50% and 100% loads, at 1800, 2300, and 2800 rpm. Addition of CNTs to the diesel fuel considerably reduced the emission of CO, CO2, HC, and NO compared to additive-free diesel fuel. Furthermore, with the addition of carbon nanotubes, the Exhaust Gas Temperature (EGT) and the Brake Specific Fuel Consumption (BSFC) decreased, while the power and Brake Thermal Efficiency (BTE) increased at all loads and speeds of the engine.
PL
Brytyjska firma Johnston Sweepers wprowadziła nowe silniki Stage 5 JCB do swojej oferty zamiatarek montowanych na ciężarówkach VT Range. Nowe, bardziej przyjazne dla środowiska silniki zostały zaprojektowane w celu spełnienia przepisów Stage 5, oferując niższą emisję spalin w porównaniu z poprzednimi silnikami typu 3b.
EN
In this paper, the author presents a study of vibrations in a passenger vehicle and the possible influence on driver’s body in the process of natural operation. The author describes the dependence of engine size and additional equipment as the possible primary source of the vibration variations and their further propagation in the entire vehicle structure. The analysis was performed on the passenger cars with naturally aspirated and turbocharged gasoline engines. The aim of this study was to verify the level of vibrations in the vehicle structure with these particular engines, especially influence of downsized power unit, during various state of engine operation. The second goal was to examine the vibrations in the specified location related to driver’s body. The measuring method used piezoelectric accelerometers, which were attached to the designated locations in the vehicle and were able to detect variations of the acceleration. The signals were collected as characteristics in the time domain. In order to achieve frequency domain for spectral analyses, the author applied the Fast Fourier Transform (FFT).
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