Temat: Expansion - Katalog OPAC zbiorów

Skocz do pozycji: 1.

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: 2.

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: 3.

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: 4.

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: 5.

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: 6.

Tytuł:: High-quality silumin on pistons of combustion engines
Autorzy:: Jankowski, A.
Pietrowski, S.
Sieminska, B.
Szymczak, T.
Powiązania:: https://bibliotekanauki.pl/articles/245889.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
piston
composite alloys
heat treatment
thermal expansion
hysteresis
Opis:: In the paper the test results are presented for the AlSH2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 newly worked out silumin close to eutectic piston-silumin with the elevated content ofcopper and nickel to approx. 5% with relation to generally applied the AISH2 piston silumin. The novel silumin contains also Cr, Mo, In and V micro alloy additions in quantity approx. 0.05 percent for every element. Research of microstructure, HB hardness and coefficient of lineal thermal expansion a for the AlSil2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 silumin in the cast state, after the separation strengthening and additional short duration high-temperature heat-treatment were performed. Research of the microstructure of the AlSH2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 silumin showed the occurrence in it following constituent phases: alfa(Al), beta(Si), Al2Cu and AlMoCrWVMgNiSiCuFe. The separation strengthening brought about the coagulation of silicon emissions. The short duration high-temperature heat-treatment caused additional coagulation of silicon emissions and also its coalescence. Measurement of the HB hardness showed high hardness investigated alloy in the rough state, approx. 30% higher from the AlSi2 piston silumin. Measurement of the a coefficient of thermal expansion showed beneficial effects of novel alloy connected with the value decreasing of this coefficient as well so called hysteresis. Further studies on novel alloy will concentrate on alloy-additional and processes of the heat treatment.
Źródło:: Journal of KONES; 2009, 16, 4; 563-573
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

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: 8.

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: 9.

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: 10.

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: 11.

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: 12.

Tytuł:: Modelling influence of temperature for assessment of wear elements of frictional joints
Modelowanie wpływu temperatury na ocenę zużycia elementów skojarzeń ciernych
Autorzy:: Pakowski, C.
Kałdoński, T. J.
Kałdoński, T.
Powiązania:: https://bibliotekanauki.pl/articles/243040.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: tarcie suche
rozszerzalność cieplna
zużycie tarciowe
dry friction
thermal expansion
abrasive wear
Opis:: In the article is presented continuous method for measurement of wear in conditions of technically dry friction of tribological cinematic pairs type pin-on-disk of T-11 tester, for example. Also is discussed modification of measurement system tester, which it makes possibility synchronization measurement respecting angle position of counter-sample. For six selected joints is appointed a correction for thermal expansion in dependence on temperature offrictional pair as well on speed of temperature change. For continuous of recorder temperature and displacement are carried out research wear for typical materials as well as is measured total wear after finish test. The analysis of obtained results shows existence of correlation between total linear experimental wear and analytical value of total linear wear takes into consideration correlations for thermal expansion. However, during friction there is not correlation between recorded change of dimensions joint and total wear. It shows correction this model. Results calculations of linear wear are overstate in relation to obtained value of wear in direct measurements. It doesn't lower possibility using established method for interpretation results of research wear
W artykule przedstawiono metodę ciągłego pomiaru zużycia w warunkach tarcia technicznie suchego węzła tribologicznego typu trzpień-tarcza przy zastosowaniu testera T-11. Omówiono modyfikację układu pomiarowego testera umożliwiającą synchronizację pomiaru z położeniem kątowym przeciwpróbki. Dla sześciu wybranych skojarzeń wyznaczono poprawkę na rozszerzalność termiczną w zależności od temperatury węzła tarcia oraz od szybkości zmian tej temperatury. Wykonano badania zużycia wytypowanych materiałów, przy ciągłej rejestracji temperatury i przemieszczenia oraz zmierzono zużycie całkowite po zakończeniu testu. Analiza uzyskanych wyników wskazuje na istnienie korelacji między sumarycznym zużyciem liniowym skojarzenia wyznaczonym eksperymentalnie a obliczoną wartością zużycia liniowego, przy uwzględnieniu poprawki na rozszerzalność termiczną. Brak jest natomiast korelacji między rejestrowaną podczas tarcia zmianą wymiarów skojarzenia a zużyciem całkowitym. Dowodzi to prawidłowości przyjętego modelu, konieczne jest jednak poprawienie jego dokładności. Wyniki obliczeń zużycia liniowego są zawyżone w stosunku do wartości zużycia uzyskanych w pomiarach bezpośrednich. Nie obniża to jednak możliwości stosowania przyjętej metody do interpretacji wyników badania zużycia.
Źródło:: Journal of KONES; 2007, 14, 2; 347-353
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

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: 14.

Tytuł:: The temperature - and stress fields of valves of IC engine
Autorzy:: Jaskólski, J.
Krzyżak, R.
Powiązania:: https://bibliotekanauki.pl/articles/243403.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: intake valve
output valve
YSZ
ferberite
scheelite
silicides
pyroxene
composite
joining of materials
thermal conductivity
radiative transfer
thermal expansion
Opis:: The paper concerns building up one exhaust valve of composite-steel and two intake ceramics-steel valves of a hypothetical adiabatic engine. The input temperatures were computed using three diverse FORTRAN95 programs, solving a shortened optical integral equation with radiative transfer, transient differential equation while starting and switching off the engine and a rod like diff. Equation with 'progonka' (Thomas) solution. The ANSYS11 programme was fed up with the output of the programs. It turns out that, generally, a mineralogical, crystal-chemical approach to the joining of materials results in stresses known from the common metal engines. Such problems as CTE enhancing (partly hypothetical) by means of doping the anionic compounds by cationic ones, swelling of structures, compressibility versus coefficient of thermal expansion (CTE) , compatibility of crystal motifs while joining, thermal shock resistance, switching the bonds, mechanical longevity, radiation protection etc were addressed. It turns out that true nature of the temperature and stress field, especially of the exhaust valve is closer to the FORTRAN temperature computation than, e.g. From the heat film coefficients (ANSYS11).
Źródło:: Journal of KONES; 2007, 14, 3; 245-252
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Carnotization of the power cycle of internal combustion reciprocating engine
Karnotyzacja obiegu tłokowego silnika spalinowego
Autorzy:: Mendera, K. Z.
Powiązania:: https://bibliotekanauki.pl/articles/244333.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: obieg teoretyczny
obieg z przedłużoną ekspansją
obieg Atkinsona
obieg Millera
wczesne zamknięcie zaworu dolotowego
późne zamknięcie zaworu dolotowego
Air Standard Cycle
Extended expansion cycle
Miller cycle
Atkinson cycle
Early Intake Valve Closure
Late Intake Valve Closure
Opis:: There are two ways to increase the thermodynamic efficiency of the engine cycle known as the carnotization of the power cycle. The first is to ensure the highest possible maximum parameters and the second is to allow the working medium to expand further than in the standard cycle. This is known generally as the over-expansion or extended expansion cycle. This paper presents theoretical and numerical investigations into the effect of extended expansion on the thermal efficiency and mean effective pressure. The performance of an air standard Atkinson cycle was considered and compared to that of the Sabathe cycle. The Miller version of extended expansion air standard cycle was analysed for both naturally aspirated and supercharged engine. Additionally, the numerical simulation of supercharged engine was also carried out. In both cases, two inlet valve closing strategies were evaluated (Early Intake Valve Closure-EIVC and Late Intake Valve Closure - LIVC). From the present investigation it is concluded that the extended expansion concept is an effective way of the carnotization of the power cycle of internal combustion reciprocating engine. The main conclusion resultanting from presented paper deals controls of closing angle of inlet valve which is to be an effective way of influence on the course of temperature changes of the working charge and what should be useful for the level emission decreasing of nitrous oxides.
Karnotyzacja obiegu silnika spalinowego tj. poszukiwanie sposobu podwyższenia jego sprawności może dotyczyć zarówno źródła górnego (sposobu doprowadzania ciepła) jak i dolnej przemiany odprowadzania ciepła Karnotyzacja źródła dolnego to wszelkie próby zmierzające do przedłużenia ekspansji czynnika roboczego. W pracy przedstawiono teoretyczną i numeryczną analizę wpływu przedłużenia ekspansji na sprawność i ciśnienie średnie obiegu silnikowego. Przeprowadzono analizę teoretyczną obiegu Atkinsona, a jej wyniki porównano z klasycznym obiegiem Sabathe. Dokonano także analizy obiegu Millera zarówno dla silnika niedoładowanego jak i doładowanego oraz zrealizowano badania symulacyjne obiegu doładowanego silnika z przedłużoną ekspansją. W obu przypadkach analizę przeprowadzono zarówno dla wczesne zamknięcie zaworu dolotowego jak i późnego zamknięcie zaworu dolotowego. Przeprowadzone badania usprawiedliwiają tezę, iż koncepcja przedłużonej ekspansji może być skutecznym sposobem karnotyzacji obiegu tłokowego silnika spalinowego. Główny wniosek wynikający z prezentowanego artykułu dotyczy sterowania kątem zamknięcia zaworu dolotowego, może być efektywnym sposobem oddziaływania na przebieg zmian temperatury czynnika roboczego i co powinno być przydatne dla ograniczania poziomu emisji tlenków azotu.
Źródło:: Journal of KONES; 2007, 14, 4; 257-264
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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