Temat: Expansion engine - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Thermodynamic analysis of medium pressure reciprocating natural gas expansion engines
Autorzy:: Farzaneh-Gord, M.
Izadi, S.
Pishbin, S. I.
Sheikhani, H.
Deymi-Dashtebayaz, M.
Powiązania:: https://bibliotekanauki.pl/articles/777996.pdf
Data publikacji:: 2015
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:: Expansion engine
thermodynamic
first law
optimization
ideal gas model
Opis:: Natural gas pressure has to be reduced from medium pressure of 1.724 MPa (250 psia) to lower pressure of 0.414 MPa (60 psia) at Town Border pressure reduction Station (TBS). Currently, the pressure reduction is carried out by throttling valves while considerable amount of pressure energy is wasted. One of the equipment which could be used to recover this waste energy is the reciprocating expansion engine. The purpose of this research is to simulate one-sided reciprocating expansion engine thermodynamically for TBS pressure range. The simulation is based on first law of thermodynamics, conversation of mass and ideal gas assumptions. The model could predict in-cylinder pressure and in-cylinder temperature at various crank angles. In addition, the effects of the engine geometrical characteristics, such as intake and exhaust port area and ports timing on the Indicated work per cycle output are investigated.
Źródło:: Polish Journal of Chemical Technology; 2015, 17, 2; 119-125
1509-8117
1899-4741
Pojawia się w:: Polish Journal of Chemical Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Coefficient of thermal expansion as a component quality estimation of alloys on pistons of combustion engines
Autorzy:: Sieminska, B.
Powiązania:: https://bibliotekanauki.pl/articles/245892.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
engine pistons
thermal expansion
coefficient of thermal expansion
Opis:: The aim of realized works in the area of materials on pistons is: low thermal expansion, small differences of coefficient of thermal expansion between heating and cooling, high stiffness at elevated temperatures, high hardness and wear resistance. Changes in thermal expansion coefficient during heating and cooling may be very large, as well as during subsequent cycles of heating and cooling of an internal combustion engine pis ton with respect to standard silumin alloys usedfor pistons of internal combustion engines. The paper presents: coefficient of linear expansion a for the AlSi standard alloy, coefficient of linear expansion a for the AlSi alloy with the apositive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the a negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive and negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive, negative and positive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the very small a differences between cooling and heating, coefficient relative elongation as afunction of temperature with the positive elongation differences between cooling and heating, coefficient relative elongation with the very small elongation differences between cooling and heating, coefficient the course of derivative as a function of temperature (T) during heating and cooling with the positive elongation differences.
Źródło:: Journal of KONES; 2009, 16, 4; 575-583
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Investigations of strength, thermal expansion and engine of novel pistons for combustion engines
Autorzy:: Siemińska, B.
Powiązania:: https://bibliotekanauki.pl/articles/243623.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engine
engine pistons
novel alloys
novel materials
thermal expansion
Opis:: Pistons of internal-combustion engines work in the conditions of high mechanical and thermal loads. The typical alloy materials applied on pistons of internal-combustion engines have inadequate parameters for such applications. It mainly refers to the fatigue strength of the mechanical and thermal character and to the thermal shocks. In relation with fact that the piston of internal-combustion engine has unsymmetrical shape, that in every case of the piston temperature increase the unequal deformations appear and stresses related with this, what causes fatigue loads of the piston structure. The paper presents special demands, which pistons of contemporary of internal-combustion engines must fulfil with respect to strength, thermal and useful properties, mirrored in the engine work parameters, like engine oil consumption, fuel consumption, noise, gas blow by to the crankcase and the emission of toxic exhaust elements, mainly hydrocarbons. One turned attention on the new material that can be used in manufacture of pistons for the internal-combustion engines, which is the carbon material. In the article the results of research for the mechanical, thermal and engine properties are submitted for the pistons manufactured from a new material. On the emphasis deserve fact, that the application of new materials permits on the obtainment of the small difference in the coefficient of linear thermal expansion during the heating and the cooling, that will bring many profitable effects of both functional and useful nature.
Źródło:: Journal of KONES; 2008, 15, 3; 471-478
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Preliminary research no vel composite materials with small hysteresis and high functional parameters for combustion engines pistons
Autorzy:: Siemińska-Jankowska, B.
Powiązania:: https://bibliotekanauki.pl/articles/246073.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
engine pistons
thermal expansion
hysteresis
Opis:: Pistons of internal-combustion engines are the most loaded elements of internal-combustion engines, belong to these specialistic elements, which have essential influence on the ecological properties of engines, their durability and reliability. The object of paper is pistons manufactured from the standard material and from new research alloy. The investigations were performed with dilatometer permitting on the registration of changes of the dimensions of sample in the function of temperature and time. The measurements are possible in straight system and in differential system. Exemplary results of investigations are presented in the paper. During the piston heating, period preutectic phases succumb the partial dissolution in solid solution a, but in the cooling process they secrete again. As a consequence the piston partial deformation occurs, which by result is gradual growth of difference between its expansibility during the warming and contraction in the process of cooling (so-called hysteresis occurs). The characteristics of the new piston silumin alloys give possibility of dearances minimalization and the obtainments of a correct engine performance in the full range of engine rotational velocities and loads. The effect are the decrease of the oil expenditure, the decrease of the emission of hydrocarbons in exhaust gases, the decrease of blowbys to crankcase, the decrease of the expenditure of piston rings grooves wear and the piston skirt wear, the decrease of the piston deformation and the increase of engine durability and reliability.
Źródło:: Journal of KONES; 2009, 16, 1; 447-452
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Researches of novel composite pistons for combustion engines
Autorzy:: Jankowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/247291.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
engine pistons
composite alloy
thermal expansion
hysteresis
engine test
Opis:: Novel composite material was worked out based on experiences and researches realized in the Institute of Aviation, the Lodz Technical University and PZL WOLA Company. Actually applied silumins on the pistons secure them high-quality for durability, low Rm and HB values at increased temperature, high hysteresis of the coefficient a during heating and cooling, high clearance between the piston and the cylinder, increased oil consumption, blowthrough and obtainment relatively low-power engine. Thereby works concerning elaborations of novel composite material based on the standard silumin with better from at present applied on the piston properties are presented. Novel composite material on the pistons has mechanical properties in the ambient temperature: Rm ≥ 400 MPa; Rp0.2 ≥ 330 MPa; A5 ≥ 3.5%; HB ≥ 130 and in the temperature 250°C: Rm ≥ 320 MPa; Rp0.2 ≥ 240 MPa; A5 ≥ 5%; HB ≥ 90. Metallographic and ATD researches, the researches of the hardness, the researches of Rm, Rp0.2 and A5, the researches of the coefficient of thermal expansion "α", engine researches were performed. Curves ATD and the microstructure the alloy are presented. Test results of the S12-U diesel engine engine are introduced too.
Źródło:: Journal of KONES; 2013, 20, 4; 141-146
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Research results of novel composite materials with low hysteresis during heating and cooling for pistons of combustion engines
Autorzy:: Sieminska, B.
Powiązania:: https://bibliotekanauki.pl/articles/245037.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: internal combustion engines
engine piston
thermal expansion
emissions
Opis:: Research results of novel silumins on pistons for combustion engines, which have high mechanical properties within the range of piston higher operating temperatures, 100-300°C, are presented in the paper. Silumins contain enlarging concentration of the nickel and copper alloy additives up to 4.0, and chrome and molybdenum alloy additives up to 1.0%. Occurrence of given microstructure in piston-silumins results in almost the same values of the coefficient thermal expansion during the heating up to the 300 °C temperature and during the next cooling into the ambient temperature. Small values of the coefficient of expansion of thermal and small differences between values of the coefficient of thermal expansion during heating and cooling enable on application of small values of working clearances between piston and the cylinder liner. As a consequence they make possible, the low exhaust emission level, and the low noise level. The pistons from alloys with small values ofthe coefficient of thermal expansion, small differences of this coefficient during heating and cooling are novel aspects presented in paper. Research results of strength and metallographic parameters, research results of the coefficient of thermal expansion, comparative engine research results are represented in the paper. In particular representative chemical components for a standard alloy and novel alloy, mechanical properties investigated alloys after solution heat treatment, wear resistance of novel alloy compared with two cast irons, ATD curves, fibrous construction, silicon construction, microstructure of novel alloy, courses of changes of the coefficient of thermal expansion in the function of the temperature during heating and cooling are presented in the paper.
Źródło:: Journal of KONES; 2010, 17, 1; 421-432
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: 6-stroke engine: thermodynamic modelling and design for testing
Autorzy:: Nimsiriwangso, Atip
Barnes, Paul
Doustdar, Omid
Wyszynski, Miroslaw L.
Mohyeldin, Gasim Mohamed Maisara
Kowalski, Miroslaw
Powiązania:: https://bibliotekanauki.pl/articles/241771.pdf
Data publikacji:: 2019
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: six-stroke engine
water injection
steam expansion
engine efficiency
dynamic gas model
Opis:: In the study AVL BOOST™ is used to perform a thermodynamic simulation of a six-stroke engine, being built by a research team based in Saudi Arabia. The six-stroke cycle consists of a standard four-stroke Otto Cycle followed by a heat recovering steam expansion cycle. Water is injected into the hot combustion chamber towards the end of the Otto expansion stroke producing steam, which is used to perform work on a piston. This process produces power using waste heat and therefore increases the overall efficiency of the engine. The Robin EY28D engine, which is a single cylinder, four-stroke, gasoline engine was used for this simulation study. The engine was modelled and converted into six-stroke engine in AVL BOOST. The results show that six-stroke engine is more efficient than four-stroke engine. In six-stroke engine, the engine power is increased by 33.1% and brake specific fuel consumption (BSFC) is decreased by approximately 16%. Where emissions are concerned, Nitrogen Oxide (NOx) emission from six-stroke engine is reduced by 80%, while the Hydrocarbon (HC) emission increases by 85% compared with the original 4-stroke. Moreover, the most efficient camshaft was found and designed according to the most efficient valve profile for this engine, which is combination of 60CA° of valve duration and 10 mm of valve lifting.
Źródło:: Journal of KONES; 2019, 26, 2; 93-106
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Researches novel materials on the pistons with low hysteresis to combustion engines
Autorzy:: Sieminska, B.
Slawinski, Z.
Powiązania:: https://bibliotekanauki.pl/articles/243012.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
engine pistons
composite alloy
thermal expansion
hysteresis
Opis:: The researches were carried out at the use of the precise dilatometer of the firm BAHR 802/801. The device makes possible the registration of changes of measurements of the sample in the function of the temperature. Measurements in the simpler and differential are possible. Heating and cooling is performed in the special device, which realizes the programme temperature, controlled computer. Changes of dimensions are measured with an inductive sensor. Samples were placed in the quartz-pipe and changes of their length were transferred by quartz-rods. The temperature of tested material was measured by means of the Pt-PtRh thermocouple. Material on the pistons has a fundamental meaning for the value of the clearances between the cylinder and the piston. Too small clearness between the piston and cylinder on the cold engine cannot be applying, because during the work of an engine it would be able to occur seizing of an engine. From here, also the large resistance on seizing of material of the piston is essential. Investigated composite materials performed based on piston-silumins AK12 and AK18 in which a composite addition was silicon carbide (SiC) and ferric sulphide (FeS).
Źródło:: Journal of KONES; 2012, 19, 4; 549-554
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Analysis and research of piston working conditions of combustion engine in high thermal load conditions
Autorzy:: Jankowska-Sieminska, B.
Jankowski, A.
Slezak, M.
Powiązania:: https://bibliotekanauki.pl/articles/243400.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engine
piston
thermal load
thermal expansion
thermal shock
Opis:: Explanation of phenomena occurring in pistons of combustion engines which appear during heating and cooling processes in reference to standard materials and composite materials of high material proprieties is aim of the paper. Bring over researches were mostly directed on measurements of difference dimensions which appear during the piston work in the combustion engine. The paper concentrates on phenomenon of different proprieties of materials. The thermal stresses and shocks differ. In the thermal shock, thermal stresses are caused by instantaneous temperature gradients which appear at high engine speed. These stresses are determined thro temperature distribution and they do not differ from stresses in steady-state conditions. Researches concerning thermal expansions were performed by means of sensitive dilatometer which can work in simple and differential system. Changes of dimensions versus temperature function were measured with inductive sensor and the sensitive Pt-ptrh thermocouple, and results were referred to reference material-Platinum. Research results are illustrated on diagrams of different courses of changes of the of thermal expansion coefficient during heating and cooling of standard and composite materials. Values of the thermal expansion coefficient a for the heating and cooling are smaller for composite alloys. The course of the coefficient â during cooling can be higher or lower from the coefficient a during heating. Similar values were also received. Maximum differences were of 10%. Smaller values of the coefficient a for composite alloys cause that for such the same thermal loads temperature gradients will be smaller for composite alloys. Courses of changes of the coefficient â have a different characteristics suited from chemical composition of alloy, granularity of the composite component and thermal treatment.
Źródło:: Journal of KONES; 2007, 14, 3; 233-243
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Some problems pistons made from composite materials with small hysteresis to combustion engines
Autorzy:: Jankowska-Sieminska, B.
Powiązania:: https://bibliotekanauki.pl/articles/245555.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
combustion engine piston
composite alloys
thermal expansion
hysteresis
Opis:: Novel composite ma hysteresisterials on the pistons are characterised that they occur in them multiple intermetallic phases which crystallize in the high temperature, before crystallization of the alfa+beta (Al+Si) eutectic. For forming of pre-eutectic phases, chromium and molybdenum are introduced to silumins, and for derivation of multiple increased concentration of nickel and copper and decreased concentration of magnesium are accomplished. On the basis of evaluations of mechanical and thermal loads of combustion engines pistons applying essence of composite materials of combustion engines pistons, as well requirements for combustion engines pistons, especially high loaded engines are expressed. Test results of hardness, influence of temperature of casting, test results of mechanical properties, friction coefficient and coefficient of thermal expansion are presented in the paper. The special attention devoted to so called hysteresis coefficient of thermal expansion and hysteresis of the relative elongation in function temperature and time. Courses of coefficient of thermal expansion for standard and composite material are presented. Differences of the a coefficient during heating and cooling in function temperature are relative to kind of heat treatment. Two-stage heat treatment is beneficial for the obtainment small values of the a coefficient.
Źródło:: Journal of KONES; 2011, 18, 3; 123-128
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: New design of the five-stroke SI engine
Autorzy:: Noga, M.
Sendyka, B.
Powiązania:: https://bibliotekanauki.pl/articles/245394.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: five-stroke engine
spark ignition
additional expansion
increase of total efficiency
Opis:: The paper describes design of the five-stroke engine developed in the Chair of Combustion Engines at Cracow University of Technology. The idea of five-stroke engine, in which the expansion ratio is significantly greater than the compression ratio has been presented by the Belgian engineer Gerhard Schmitz. The prototype of such an engine was made by Ilmor Engineering. Engine developers have released results of preliminary research, but there is no detailed information on the toxic exhaust emissions. For this reason, at Cracow University of Technology the research was undertaken to determine the impact of implementing the five-stroke cycle into the engine with spark ignition to reduce toxic emissions and increase total efficiency. To achieve this goal, the test engine was built, which is based on a concept similar to the idea of Gerhard Schmitz, with the difference that it has not been designed from the ground up, and it is based on an existing four-cylinder four-stroke engine. In comparison with the original solution, the engine built in Cracow has a completely different design of timing system, four valves per cylinder and petrol direct injection. This paper presents a detailed description of the engine design and the results of its preliminary research. The results of the tests of the five-stroke engine confirm an increase of specific torque and power (related to unit of engine displacement) and improve of total efficiency within a certain range of the engine map.
Źródło:: Journal of KONES; 2013, 20, 1; 239-246
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Thermomechanical FE analysis of the engine piston made of composite material with low histeresis
Autorzy:: Szurgott, P.
Niezgoda, T.
Powiązania:: https://bibliotekanauki.pl/articles/244407.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: engine piston
composite piston
coefficient of thermal expansion
thermal analysis
FE analysis
Opis:: The main purpose of the preliminary analyses presented in the paper was to compare the behaviour of the combustion engine piston made of different type of materials under thermal load. A thermomechanical FE analysis of the engine piston made of composite material was shown. A selected engine is installed in one of the popular polish tanks. The proposed new material is characterized by a low hysteresis – the differences of the coefficient of thermal expansion for heating and cooling are not significant. The results obtained for the piston made of a new material were compared with those for the current standard material. The piston was loaded by a temperature field inside it. Appropriate averaged thermal boundary conditions such as temperatures and heat fluxes were set on different surfaces of the FE model. FE analyses were carried out using MSC.Marc software. Development of the FE model was also presented. Geometrical CAD model of the piston was developed based on the actual engine piston, which was scanned using a 3D laser scanner. A cloud of points obtained from the scanner was processed and converted into a 3- dimensional solid model. FE model of a quarter part of the piston was developed for the preliminary analysis presented in the paper. 4-node tetrahedron finite elements were applied since there was no axial symmetry of the considered object. The temperature field inside the piston was determined and presented in the form of contour bands. Contours of displacement and stress in a radial direction were shown as well.
Źródło:: Journal of KONES; 2011, 18, 1; 645-650
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Increase of efficiency of SI engine through the implementation of thermodynamic cycle with additional expansion
Autorzy:: Noga, M.
Sendyka, B.
Powiązania:: https://bibliotekanauki.pl/articles/200877.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: innovative five-stroke engine cycle
Carnot cycle
Otto cycle
five-stroke engine
additional expansion
increase of thermal efficiency of the five-stroke engine cycle
Opis:: The paper presents the theoretical basis and practical implementation of the concept of a five-stroke cycle where an additional expansion of the working medium is achieved in a separate cylinder. The work, carried out at the Cracow University of Technology, constitutes a development of the idea of five-stroke engine. This paper proposes a new theoretical thermodynamic cycle that describes the processes occurring in a five-stroke engine. It has been taken into consideration that the expansion ratio of the engine is twice the compression ratio. At the next step an analysis of the thermodynamic cycle with particular emphasis on its thermal efficiency compared to efficiency of four-stroke engine has been shown. In the second part of the article selected research results of the five-stroke engine built based on the existing four-cylinder spark ignition engine have been presented. A comparison of the total efficiency obtained by the engine in the four- and five-stroke version has been provided. Similar comparisons for specific emission of the selected exhaust components have also been given.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 2; 349-355
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: The Szymkowiak’s over-expanded cycle in the rocker engine with the variable compression ratio - kinematics
Autorzy:: Szwaja, Stanisław
Szymkowiak, Mirosław
Powiązania:: https://bibliotekanauki.pl/articles/2097629.pdf
Data publikacji:: 2022
Wydawca:: Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:: rocker
engine
linkage
over-expanded cycle
variable expansion ratio
variable compression ratio
wahacz
silnik
połączenie
zmienny stopień rozprężania
zmienny stopień sprężania
Opis:: 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.
Źródło:: Combustion Engines; 2022, 61, 2; 68--72
2300-9896
2658-1442
Pojawia się w:: Combustion Engines
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Termo-mechaniczna analiza naprężeń i odkształceń zespołu cylindra silnika spalinowego jako próba wyjaśnienia niekontrolowanego zapłonu mieszanki paliwowo-powietrznej
Thermo-mechanical analysis of stress and deformation of engine cylinder block assembly as the attempt to explain an uncontrolled ignition of air-fuel mixture
Autorzy:: Michalski, J.
Woś, P.
Powiązania:: https://bibliotekanauki.pl/articles/309904.pdf
Data publikacji:: 2018
Wydawca:: Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:: połączenie skurczowo-rozprężne
zespół cylindra silnika
stan wytężenia tulei
stan wytężenia kadłuba cylindra
silnik lotniczy
zapłon samoczynny
szczelina
pełzanie materiału
model analityczny naprężeń
compression-expansion joint
engine cylinder device
cylinder stress pattern
aircraft engine
compression ignition
gap
creep
analytical stress model
Opis:: W pracy przeprowadzono analizę możliwej przyczyny występowania samoczynnego zapłonu mieszanki paliwowo-powietrznej lotniczego silnika spalinowego obciążonego mocą maksymalną podczas badań na hamowni silnikowej. Takie objawy niepoprawnej pracy silnika mogą występować także w locie samolotu i śmigłowca. W celu wyjaśnienia przyczyny niepoprawnej pracy silnika zastosowano nieliniową analizę metodą elementów skończonych. Określono dyskretny model uproszczonego układu zespołu cylindra silnika obejmujący kadłub i tuleję cylindrową. W analizie numerycznej uwzględniono zarówno siłę mechaniczną, wynikającą z obciążenia zaciskiem tulei cylindrowej w kadłubie jak i obciążenie ciśnieniem czynnika roboczego oraz obciążenie nierównomiernym polem temperatury. Przemieszczenia i naprężenia w tulei i kadłubie obliczono metodą elementów skończonych za pomocą systemu PATRAN oraz systemem ABAQUS. Wynikło to z konieczności uwzględnienia silnej anizotropii właściwości tulei cylindrowej z żeliwa szarego podczas rozciągania i ściskania. Geometrię części modelowano elementami płaskimi o topologii czterowęzłowej z elementami kontaktowymi dwuwymiarowymi sprzęgającymi. Analitycznie wyznaczono także naprężenia zginające w zespole cylindra wywołane obciążeniem bocznym tłoka silnika poprzez uwzględnienie ciśnienia czynnika roboczego, sił masowych i siły tarcia. Obciążenie ciśnieniem i temperaturą zespołu cylindra określono w wyniku badań stanowiskowych silnika. Charakterystyki materiałowe żeliwa szarego i żaroodpornego stopu aluminium wyznaczono doświadczalnie. Wyniki nieliniowej analizy statycznej naprężeń i odkształceń dla połączenia tuleja cylindrowa-kadłub wykazały, że w obszarze zwrotu zewnętrznego pierścieni tłokowych wystąpiły wysokie naprężenia i odkształcenie plastyczne tulei cylindrowej, wywołujące brak styku połączenia tych elementów. Zakłóca to przepływ ciepła z tulei cylindrowej do kadłuba i stwarza możliwość niekontrolowanego zapłonu mieszanki paliwowo-powietrznej. W silniku istnieje konieczność stosowania zacisku średnicowego tulei w cylindrze w granicach 0.21÷0.42 mm, co wynika z rozszerzalności cieplnej elementów w warunkach jego pracy z maksymalną prędkością obrotową i obciążenia maksymalną mocą. Połączenie skurczowo-rozprężne tulei z cylindrem dla największego zacisku powoduje odkształcenie plastyczne żeliwa szarego tulei cylindrowej. Wymagana jest zmiana gatunku lub rodzaju żeliwa o wytrzymałości doraźnej powyżej 400 MPa.
The paper analyzes the possible cause of self-ignition of air-fuel mixture in spark-ignition internal combustion engine loaded with maximum power during tests on the engine dynamometer stand. It leads to incorrect engine operation and may also occur during the flight of an aircraft or helicopter. In order to explain the cause of incorrect engine operation, a non-linear analysis using the finite element method was applied. A discreet model of a simplified engine cylinder assembly system comprising a cylinder body and the liner was determined. The numerical analysis includes both the mechanical force resulting from loading the cylinder liner clamp in the body as well as the pressure of the working medium pressure and the load on the non-uniform temperature field taken from engine test-bed measurements. The results of nonlinear static analysis of stresses and strains for the cylinder body-liner connection have shown that in the area of TDC where outer piston ring turns back, high stresses and plastic deformation of the cylinder liner occurr, causing a lack of contact between these elements. This disrupts the heat transfer from the cylinder liner to the cylinder body and creates the possibility of uncontrolled ignition of the fuel-air mixture.
Źródło:: Autobusy : technika, eksploatacja, systemy transportowe; 2018, 19, 6; 609-618, CD
1509-5878
2450-7725
Pojawia się w:: Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:: Biblioteka Nauki

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