Temat: TWO - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Modelling of process of injection and combustion in two - cycle engine
Autorzy:: Cygnar, M.
Powiązania:: https://bibliotekanauki.pl/articles/246482.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: two cycle engine
two fuel injection systems
Opis:: Article presents simulated research and visualization of combustion process of four-cylinder test engine based on the spark ignition engine Toyota Yaris 1.300 cm3, equipped with two systems of power supply i.e. : fundamental and ignition. Two methods of initiating the combustion process were applied in the engine, that is : from spark ignition and after it has turned off - the combustion is initiated by means of the injection of the ignition dose. The conducted research was aimed at revealing the differences in the combustion process and the engine performance, especially the changes of pressure in the cylinder for that kind of dual-fuel power engine supply. The ignition dose injected to cylinder was equal to about 5% of the general mass of the fuel given to the engine. The mass of the fuel injected to the infold manifold determined the remaining part, and direct injection of fuel took place for several dozen rotation degrees of the crankshaft before TDC (Top Dead Centre). A spatial grid of the engine's model (preprocessor) was created as well as the modification of the source KIVA 3V program was executed, consisting of taking into account two systems of injection. It is necessary to mention, that KIVA 3V program contains only one source of fuel's injection as a default. On two-dimensional graphs, the courses of changes of pressure and temperature are presented as well as the change of the mass of the injected ignition dose. A simulation was conducted for chosen rotation angles of the crankshaft, for the purpose of a radical analysis of thermodynamic parameters along with an analysis of the toxic components of the exhaust fumes. The conclusions of the conducted simulated research confirm the reduction of fuel consumption with a simultaneous reduction of the emissions of toxic exhaust fumes components.
Źródło:: Journal of KONES; 2012, 19, 3; 75-84
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Analysis of parameters of the engine working in two thermodynamic cycles
Autorzy:: Cygnar, M.
Powiązania:: https://bibliotekanauki.pl/articles/247920.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: two cycle engine
two fuel injection systems
Opis:: The article presents an experimental research conducted on a test engine based on a driving unit with a spark ignition Toyota Yaris 1,300 cm 3, equipped with two systems of power supply i.e.: fundamental and ignition. Two methods of initiating the combustion process were applied in the engine i.e.: from spark ignition and after it has turned off - the combustion is initiated by means of the injection of the ignition dose. The fundamental task of The adaptation of two power supply systems for a combustion engine is the possibility of work in two thermodynamic circulations, which permits better conditions for creating the fuel-air mixture, which translates directly into significant improvement of the engine's working parameters accuracy, such as general efficiency as well as the individual fuel consumption. The experimental research presented in this work consist of designing and construction of an engine with two injection systems with a controller managing the automatic change of the work mode, as well as the execution of the analysis of the chosen work parameters in a two-cycle engine i.e.: - comparative research on the engine's work performance, when it works with a spark ignition and when it is initiated with the autoignition of the ignition dose, - determining the increase in the general efficiency of the two-cycle engine, working with the injection of the ignition dose, in comparison with the conventional power supply system with the initiation of the combustion process from an electric discharge between the spark plug electrodes. Applying the two-cycle engine with two power supply systems with an automatic spark ignition presented in this article, along with the electronically controlled system of changing the ignition method, increases the general efficiency in the total range of rotational speed, compared with the conventional engines with the automatic spark ignition
Źródło:: Journal of KONES; 2012, 19, 2; 95-102
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Gas exchange in valved two-stroke SI engine
Autorzy:: Buczek, K.
Mitianiec, W.
Powiązania:: https://bibliotekanauki.pl/articles/245914.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
engine development
two-stroke engine
boosting
Opis:: The paper describes the work of high speed charged spark ignition overhead poppet valve two-stroke engine, which enables to achieve higher total efficiency and exhaust gas emission comparable to four-stroke engines. The work of such engines is possible by proper choice ofvalve timings, geometrical parameters of inlet, outlet ducts and charge pressure. The engine has to be equipped with direct fuel injection system enabling lower emission of pollutants. The work is based on theoretical considerations performed in GT-Power in previous authors' research and carried out in CFD code (KIVA 3 V) for different engine configurations. The initial results included in the paper show influence of inlet port geometry and charge pressure on engine scavenging process. Additionally, optimum fuel spray injector position was considered in order to obtain proper fuel vaporization and avoid significant wall-wetting. The simulation results show that the nitrogen oxides arę considerably reduced in comparison to four-stroke engines because ofhigher internal exhaust gas recirculation. The innovation of this proposal is applying of poppet intake and exhaust valves with turbocharging in the two-stroke engine and obtaining a significant downsizing effect. The conclusion shows the possibilities of proper gas exchange process in this type of two-stroke engine and thus, the feasibility of its application as a power unii for transportation means with higher total efficiency than traditional engines with possible change of engine work in two modes: two- and four-stroke cycles.
Źródło:: Journal of KONES; 2010, 17, 1; 73-80
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Modeling of selected phenomena governing surface icing
Autorzy:: Sznajder, J.
Powiązania:: https://bibliotekanauki.pl/articles/248155.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: icing
transport
air transport
simulation
two-phase flow
Opis:: Atmospheric icing poses a threat for safety in many areas of transport, especially in air transport and exerts harmful impact on operation of external sensors and mechanisms of aircraft, ships and land vehicles. In order to investigate phenomena leading to ice accretion on sensitive parts of objects exposed to icing conditions numerical simulation models are in use. These models are typically composed of submodels dealing with a fragment of the complex phenomenon of ice accretion and its interaction with external flow. A practical approach to simulation of icing process is to divide it into three problems being solved interactively: 1) simulation of two-phase flow of air and dispersed supercooled water and determination of distribution of mass of water hitting the object’s surface, 2) determination of conditions on the surface collecting supercooled water from the external flow and simulation of freezing and water film flow, and 3) modification of computational grid as a consequence of change of shape of the surface with deposits of ice. A simulation system directed at investigation of atmospheric icing on moving object is being developed as an extension of capabilities of a commercial CFD code ANSYS FLUENT. Solutions of two-phase flow of air and dispersed water with specific boundary conditions enabling the determination of distribution of water hitting the surface, as well as results of modelling of water film flow on the surface will be presented. The system of equations describing the transport of the dispersed water consists of the continuity and momentum equations. It is assumed, that interactions between the phases are onedirectional, i.e. the air flow influences the water droplet flow and not vice-versa. It is also assumed that the water film velocity distribution is linear in direction normal to surface. This way, both phenomena are being described with first order partial differential equations with respect to space and time and the solution approaches may be similar.
Źródło:: Journal of KONES; 2013, 20, 2; 377-384
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Analysis of direct fuel injection in a small power two-stroke engine
Autorzy:: Mitianiec, W.
Forma, M.
Powiązania:: https://bibliotekanauki.pl/articles/242265.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
engine development
two-stroke engine
direct fuel
Opis:: Small power two-stroke engines can be competitive in regard of work parameters and pollutants emission in relation to four-stroke engines at some modifications, particularly changing of fuelling system. The paper presents a modifted air-assisted direct fuel injection in a two-stroke engine, which changes propagation of fuel jet in the combustion chamber. The main problem of mixture formation is short time for fuel evaporation after injection which should begin after closing of the exhaust port. The paper shows interaction between the scavenge air, additional air stream and fuel jet from the injector located in the cylinder head, which can induce the small size of fuel droplets and fast evaporation. The computational results of fuel mixture formation and combustion process in direct fuel injection two-stroke engine Robin EC-12 with capacity 115 cm3 are presented. The simulation was carried out by use KIVA code with assumption of initial parameters from the experimental tests on the carburetted engine. Setting of the injector in a regard of the cylinder head decides of fuel motion and evaporation in the combustion chamber. Air-assisted fuel injection influences on higher mixing of fuel and better combustion than by using DFI system. The paper shows phases of mixture formation, combustion and concentration of the combustion product in the cylinder with additional air stream. Spray guided high pressure direct injection system in SI two-stroke engine enables fulfil the restrictions of gas emission of one-wheeler vehicles and small power units.
Źródło:: Journal of KONES; 2009, 16, 2; 337-347
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Numerical calculations of RVE dimensions for two-phase material
Autorzy:: Miedzińska, D.
Niezgoda, T.
Powiązania:: https://bibliotekanauki.pl/articles/242298.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: microstructure
two-phase material
metal-ceramic composite
RVE
Opis:: A representative volume element (RVE) is a statistical representation of typical material properties. It should contain enough information on the microstructure thereby be sufficiently smaller than the macroscopic structural dimensions. The paper deals with the numerical calculations of the dimensions of the RVE for a two-phase material microstructure. Two and three dimensional models are taken into consideration. The structure of the samples are developed on the base of randomization of elements belonging to one of the phases. The phases volume share is 50/50%. The following series of the models are analyzed: from 10 x 10 to 100 x 100 elements for 2D samples and from 10 x 10 x 10 to 100 x 100 x 100 elements for 3D samples. The element characteristic dimension is 10 jm. The elastic behavior of the base materials (magnesium and alumina) is taken into account. The quasi-static compression tests of the developed structures are carried out with the use of LS-DYNA computer code. The results are presented as the equivalent Young modulus values and compared to the calculations based on the rule of mixtures. The stabilization of the achieved results allows to assess the dimensions of the RVE for two-phase material with random distribution.
Źródło:: Journal of KONES; 2011, 18, 2; 303-310
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Thermal state simulation for cylinder of marine two stroke engine
Autorzy:: Kowalski, J.
Powiązania:: https://bibliotekanauki.pl/articles/244344.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: marine two-stroke engines
modelling
radiosity
heat transfer
Opis:: This paper deals with the modelling of heat flow through cylinder liner structural components of a two-stroke engine. Especially, I paid attention to simulating temperature distribution for the wet cylinder liner. Multidimensional equations for the transient heat conduction with the Dirichlet and Fourier boundary conditions have been applied. In particularly, local values for the convective and radiative heat transfer coefficients using the Fourier boundary conditions determined in space of cylinder volume are applied. In order to determine the temperature distribution for the considered space, the radiosity method is used. Simulation results have been presented in the form of a temperature field for cylinder liner structural components depending on the crankshaft position angle. Application of the iterative calculation method for solving differential equations of energy balance allowed me to use software easy to get. I carried out all iterative computations using MSEXCEL spreadsheet. This way, I could decrease the simulation cost significantly. The simplicity of such an approach allowed me to apply the obtained results for visualization of the conduction heat transfer phenomena occurring in a cylinder of working marine engine. The presented approach could be used for the development of ship machinery simulators as well.
Źródło:: Journal of KONES; 2007, 14, 4; 209-216
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Investigation into the effect of bore/stroke ratio on a single cylinder two stroke opposed piston engin
Autorzy:: Alqahtani, A. M.
Wyszynski, M. L.
Mazuro, P.
Powiązania:: https://bibliotekanauki.pl/articles/245226.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: opposed-piston
two-stroke
AVL Boost
thermodynamic modelling
Opis:: Opposed-piston (OP) engine’s promising fuel efficiency has attracted the interest of automotive industry in the recent years. The opposed-piston two-stroke (OP2S) engine technology heightens this fuel efficiency benefit and offers advances in structure, power density and thermal efficiency whilst sustaining its lower cost and weight. Today thermodynamic modelling remains an indispensable and cost effective route in the development and optimisation of internal combustion engines (ICEs). To achieve this goal, the OP2S engine is simulated and validated against experimental results in AVL Boost™, which is hailed as one of the most reliable and advanced engine simulation tools. Detailed analyses of the piston dynamics, heat release, scavenging and heat transfers are highlighted in discrete sections of this paper. Having compared distinct heat release models, the Wiebe 2-Zone model emerged efficacious in replicating the heat release characteristics of the PAMAR™ engine. In comparing the numerical and experimental results, the simulation revealed minimal differences in peak pressure, peak temperature and maximum pressure raise rate, under ±2.5% differences for indicated power, IMEP, indicated thermal efficiency (ITE) and ISFC. Subsequently, confidence taken from the validated numerical model is then deployed to investigate the effect of stroke-to-bore (S/B) ratio on OP2S performance. Three combinations of S/B ratios (0.5, 1.25, and 1.69) with identical swept volume are analysed in this study. Utilisation of the validated model ensured the standardisation of intake, exhaust and the combustion systems in order to isolate the effects of S/B ratio. Results indicate that heat losses decrease with increasing S/B ratio because of the reduced surface area-to-volume in the cylinder. Consequently, an improvement in ITE and mechanical efficiency is observed with reduced ISFC for higher S/B ratios. A tendency of upsurge in combustion efficiency is also evident for higher S/B ratio due to reduced heat transfer near minimum volume of the combustion chamber.
Źródło:: Journal of KONES; 2016, 23, 2; 9-16
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: Analysing the cavitation phenomena in in-nozzle flows
Autorzy:: Vajda, B.
Žunič, Z.
Kegl, B.
Powiązania:: https://bibliotekanauki.pl/articles/247508.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: two-phase flow
cavitation
injector nozzle
CFD
nodalisation analysis
Opis:: The geometry of the diesel fuel injection nozzle and fuel flow characteristics in the nozzle significantly affects the processes of fuel atomization, combustion and formation of pollutant emissions in diesel engine. To improve the process of fuel injection, CFD packages are used. Since CPU times are often high, partial models are used for the analysis. In presented paper the influence ,of different density of mesh on the cavitation phenomena is being analysed. The theoretical backgrounds of the cavitation occurrence presented in the first part of the paper are followed by the numerical analyses of two-phase flow in same simplified nozzle models. The numerical analyses are made using computation fluid dynamic (CFD) program Fire. The numerical analysis is made for two different types of fluid, diesel (D2) and biodiesel (B 100). Numerical analysis also includes various densities of meshes and their influence on results. The two-phase flow is analysed using a two-equation approach, where all conservation equations are solved for every phase. Numerical analysis results are compared to the experimental observations of the two-phase flow available from the literature. The results are compared for various meshes and various fluid types. The results show that higher pressure yields mode cavitation and point out the importance of mesh densities.
Źródło:: Journal of KONES; 2010, 17, 2; 475-482
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: A valved two stroke engine as a new power source
Autorzy:: Mitianiec, W.
Buczek, K.
Powiązania:: https://bibliotekanauki.pl/articles/245638.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
engine development
two-stroke engine
valve timing
pollutants
Opis:: The present work defines main conception of modern, efficient and ecologic two-stroke engine. It indicates the scope of necessary modifications that have to be made in typical four-stroke engine to prepare it to work in two-stroke mode. Taking into account some limitations (especially in valve train design) authors performed several analyzes in order to check the possibility of proper scavenging process and obtain main engine characteristics. The paper contains description of simulation approach and selected mathematical models that was applied in carried over analyzes. The results of foregoing simulations, which were obtain taking advantage of GT-Power software should be considered as preliminary since several parameters have to be defined during research and 3D simulations. In order to expose advantages of modern two-stroke engine a simple comparison of it and its predecessor was performed taking into consideration BSFC maps. The objects of simulation were fluid flow, scavenging and combustion. This comparison indicates that proposed two-stroke engine achieve significantly less break specific fuel consumption (up to 27 g/kWh drop). Paper presents diagram of new type two-stroke engine with poppet valves, which is probably the most feasible layout of two-stroke engine, and GT-Power model of simulated single-cylinder engine based on four-stroke single cylinder engine.
Źródło:: Journal of KONES; 2009, 16, 3; 259-268
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 11.

Tytuł:: Simulation of work of an engine working with combustion initiation from ignition dose of fuel
Autorzy:: Sendyka, B.
Mitianiec, W.
Noga, M.
Powiązania:: https://bibliotekanauki.pl/articles/245989.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: modelling
simulation
combustion engine
HCCI
two stage injection system
Opis:: The paper presents analysis of fuelling and of the course of combustion process for a two-cycle engine. The main idea of the engine according to patent solution of Prof. B. Sendyka consists in the fact that engine work begins from spark ignition, whereas, at higher load and higher temperature in the cooling system there occurs switching off spark ignition and transition to ignition from an ignition dose injected directly into the combustion chamber. Such an engine possesses two injection systems: one system of multi-point injection which forms homogenous mixture, whereas, the other system of direct injection is used for ignition dose injection only. After injection of the ignition dose of a very small mass combustion is initiated on the basis of formation of auto-ignition centres so as it takes place during knock combustion. Auto-ignition centres initiate combustion of the basic charge. Simulation was carried out in order to perform analysis occurring phenomena of fuel feeding and combustion. Works on it started from elaboration of a computational grid of the engine and subsequently analysis of indicated diagrams of engine work with injection of ignition dose was performed. Analysis was also performed of temperature traces and of traces of charge mass change in the cylinder as well as of participation of the mass of basic fuel dose in the cylinder in function of the crank angle. Moreover visualization of effects of the process of mixture formation and combustion was performed and presented in form of illustrations of charge temperature distribution, fraction of fuel ignition and basic dose vapours in cross-sections of the combustion chamber.
Źródło:: Journal of KONES; 2011, 18, 3; 395-403
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 12.

Tytuł:: Determination of the total efficiency for engine with spark - ignition and compression - ignition
Autorzy:: Cygnar, M.
Budzik, G.
Powiązania:: https://bibliotekanauki.pl/articles/246712.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: two fuel injection systems
spark-ignition
compression-ignition engines
Opis:: This paper presented of developing a power system for two fuel injection systems – spark ignition and compression ignition. Two ways to initiate combustion process were used: initially the spark ignition, and after it turns off - the combustion is initiated by the injection of ignition injected fuel. The composition of the ignition dose was developed through the research conducted in order to adjust the right proportions of chemical components to obtain the best parameters of the combustion process. The study considered the performance of the ignition dose injected into the engine cylinder and its evaporation process, the charge stratification, the formation of toxic emission and the total efficiency of the engine. Experimental studies were carried out on a test engine equipped with two injection systems and automatic mode change control management. The scope of research included: – determining the basic characteristics of the engine operation, taking into account the injection advance angle of the ignition dose, – comparative studies of engine performance and exhaust gas composition, working with spark ignition and initiated by compression ignition of the ignition dose, – determining the increase in the general efficiency of the two-circulation engine working with injection of ignition dose compared to conventional power system with the initiation of combustion process from the spark plug.
Źródło:: Journal of KONES; 2013, 20, 1; 41-48
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 13.

Tytuł:: Changes of the 2-stroke aerosol in the exhaust sampling system
Autorzy:: Czerwinski, J.
Comte, P.
Mayer, A.
Reutimann, F.
Powiązania:: https://bibliotekanauki.pl/articles/247914.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: scooters
two-stroke direct injection
carburettor
2-stroke aerosol
nanoparticulate emissions
Opis:: Nanoparticle emissions of two 2-stroke scooters were investigated along the exhaust- and CVS-system (Constant Volume Sampling) with closed and with open line (cone). Due to their technology, the scooters produce different kind of aerosol (state of oxidation & SOF-content) and in addition to that they were operated with and without oxidation catalyst. The scooters represent a modern technology with direct injection TSDI* ) (two stroke direct injection) and with carburettor. The tests were performed at two constant speeds of the vehicles (20 km/h & 40 km/h) according to the measuring procedures, which were established in the previous research in the Swiss Scooter Network. The nanoparticulate emissions were measured by means of SMPS (CPC) and NanoMet (abbreviations see at the end of this paper). The most important results are: - the changes of the PSD's of the aerosol along the exhaust and CVS-system are connected to the average gas temperature and PC-concentration, which result after the different dilution steps and cooling down in the connecting pipe, - in the "open" variant of exhaust gas extraction there is a dilution step with unfiltered ambient air directly after tailpipe. This causes a stop of agglomeration, reduction of diffusion loses and increased background NPconcentration. There is also lower post oxidation of CO & HC. In some cases spontaneous condensates due to the temperature drop are supposed, - with the "closed" variant there is a stronger reduction of SMPS PC's along the gas way, than with the open variant. This is to explain with the higher temperatures and concentrations in the closed system, which enable more intense thermophoresis - and diffusion losses, - the NP-concentrations measured with "open" variant are always higher, - most intense oxidation is observed with Peugeot Carb: due to the SAS, rich tuning and a relatively high temperature level there are oxidation effects already without catalyst (temp. approx. 350 centigrade). With catalyst the temperature is in the range of 400centigrade and the oxidation is so intense, that the particles are nearly eliminated. The type of sampling: "open", or "closed" as well as the sampling position in the exhaust installation have significant influence on the measured nanoparticles emission results.
Źródło:: Journal of KONES; 2012, 19, 2; 109-119
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 14.

Tytuł:: Test bed studies of an engine with combustion initiation from ignition dose of fuel
Autorzy:: Sendyka, B.
Noga, M.
Powiązania:: https://bibliotekanauki.pl/articles/245825.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: two-cycle engine
compression ignition
spark ignition
total efficiency of engine
Opis:: Results of test bed studies of combustion engine with work possibility with application of spark ignition and combustion from ignition dose injected directly into the combustion chamber were described in this article. In engine working according to the patent solution of Prof. B. Sendyka, during start and work at low rotational speed and low load a system realizing spark ignition of homogenous mixture formed in classical way in the intake manifold is active. For higher rotational speeds and heavy load the ignition system is switched off whereas, injectors of ignition dose injecting fuel by the end of the compression stroke directly into the working space of the engine are activated. The fuel dose injected into the combustion chamber undergoes auto-ignition and in this way the combustion process in the whole volume of the homogenous combustion charge accumulated in the cylinder is initiated. The mass of ignition dose of fuel constitutes about 5 – 10% of the whole fuel mass per working cycle what differs decisively the presented solution from other known engines working according to similar principles. Application of two combustion system in four stroke combustion engine aims at combining the advantages of spark ignition a compression ignition engines. The engine is characterized by easy starting and during work at higher rotational speed and higher load in the mode of ignition from pilot dose exploitation efficiency of energy contained in fuel is higher than for spark ignition engine, this finds direct reflection in increase in total efficiency by over 9% as related to the base value.
Źródło:: Journal of KONES; 2011, 18, 4; 427-509
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 15.

Tytuł:: Determination of ice deposit shape and ice accretion rate on airfoil in atmospheric icing conditions and its effects on airfoil characteristics
Autorzy:: Sznajder, J.
Sieradzki, A.
Stalewski, W.
Powiązania:: https://bibliotekanauki.pl/articles/242499.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: aerodynamics
two-phase flow
simulation of ice accretion
aircraft engineering
transport
vehicle
Opis:: Simulations of ice accretion on airfoil in icing conditions were conducted using ice accretion model implemented by authors in ANSYS FLUENT CFD solver. The computational model includes several sub-models intended for simulations of two-phase flow, determination of zones of water droplets impinging on the investigated surface, flow of water in a thin film on airfoil surface and heat balance in air-water-ice contact zone. The method operates in an iterative loop, which enables determination of effects of gradual deformation of aircraft surface on airflow over the surface, which has impact on distribution of collected water, flow of water film over the surface and local freezing rates. The implementation of the method in CFD solver made it necessary to complement the mathematical model of determination of local rates of deformation of aircraft surface with modification of computational mesh around the surface, which must conform, to the deformed surface. Results of simulated ice accretion on NACA 0012 airfoil were compared with results of experiment conducted in icing wind tunnel for a 420 s long process of ice accretion in steady-flow, steady angle-of-attack conditions. Close agreement of values and location of maximum ice thickness obtained in experiment and in the flow, simulations can be observed. For the airfoil deformed with ice, contour determination of its aerodynamic characteristics at several other angles of attack was conducted proving dramatic degradation of its aerodynamic characteristics due to ice deformation.
Źródło:: Journal of KONES; 2017, 24, 2; 271-278
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "TWO" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język