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Tytuł:
Selection of cutting parameters of turning the Ni-Al and Ni-Al-Al2O3 flame sprayed coatings
Autorzy:
Starosta, R.
Chabowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/246281.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermal spray coatings
coating turning
CBN
Opis:
The process of flame sprayed is a technology affordable and easy to implement. It does not reąińre great skill of the operator. This method is not associated with expensive workstation equipment. It may therefore be used with successfor the regeneration of machine parts bv the crew of vessel engine room. Flame sprayed coatings are characterized by porosity, oxide inclusions presence and large real area of surface. In order to obtain adequate surface roughness coatings must be applied finishing. For this purpose, the turning and grinding are used. In the paper a turning to finishing flame sprayed coatings was proposed. Coatings of Ni-5%Al and Ni-5% Al-15% Al2O3 obtained by powder flame spraying, were studied. Torch of "Casto-Dyn 8000" was used. In practice, the substrate and the t herma l ly sprayed coating are processed by the same cutting tool. For example, Messner Eutectic Castolin company offers r\vo types of tools: "Rototool II/" (square insert) and "Rototool III" with a removable cylindrical insert. Average surface roughness of coating after machined tool "Rototool II" was Ra = 3 mi m. This surface often requires grinding. The different tool geometry was suggestedfor better texture of coatings surface. Workpiece was machined by tool with CBN insert WNGA080408S01030A mounted in holder DWLNRL-2525M08 (cutting inserts beta = 80°, approach angle Kr = 95°, nose radius - 0.8 mm, relief angle alfa = 6°, rake angle gamma= -6°). The influence of cutting speed, feed rate, depth of turning on the coating surface roughness was estimated. The following cutting parameters: cutting speed Vc = 45-214 m/m in, feed rate f = 0.06-0.2 mm/rev, depth of cut ap = 0.05-0.3 mm. The lowest value of the roughness of the alloy (Ra = 0.5 mi m) and composite (Ra = 0.8 mi m) coatings were obtained by using cutting parameters: Vc = 214 m/min, f= 0.06 mm/rev, ap = 0.4 mm.
Źródło:
Journal of KONES; 2010, 17, 4; 463-469
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of thermodynamic cycle influence of turbofan mixer engine on its performance
Autorzy:
Jakubowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/245722.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aircraft engines
turbojet engines
modelling of turbojet engines
turbojet engine characteristics
Opis:
The turbofan engines are widely used as propulsion of the contemporary airplanes. In the military application the turbofan mixer engines are used. Although the turbofan mixer engines are applied for a long time, the information about exact analysis of their thermodynamic cycle and performance are still in complete. The thermodynamic cycle of the turbofan mixer engine is presented and discussed in this paper. Based on it the cycle parameters selection is discussed. Then the optimization of turbofan mixer engine cycle is presented. Final results present the influence of chosen engine cycle parameters on the engine performance. The results are analyzed and discussed. On the basis of them the conclusions are formulated. It is not such an easy process to choose for the turbofan mixer engine thermodynamic parameters. It is connected with the fulfilment of two important rules. The equalization of total pressure of mixer inflow streamfor mixer efficient work is the first of it. The other rule is connected with engine cycle optimization. As it is shown it is not possible to choose engine parameters to reconcile the demands of specific thrust maximization and specific fuel consumption minimization. The engine thermodynamics parameters selection process is the search of the compromise between these two demand fulfilments, very often including engine mass analysis.
Źródło:
Journal of KONES; 2009, 16, 4; 171-178
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of burnishing on the corrosion properties of Ni-5%Al AND Ni-5%Al-15%Al2O3 coatings obtained by plasma spraying
Autorzy:
Starosta, R.
Powiązania:
https://bibliotekanauki.pl/articles/245849.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
plasma spraying
composite coating
Ni-Al
burnishing
corrosion
polarization test
EIS test
Opis:
The Ni-5%Al alloy coatings and Ni-5% Al-15%Al2O3 composite coatings were obtained by plasma spraying method. The PN120 gun was used. The coatings onto a shaft made of austenitic stainless steel (X5CrNi 18-10) were sprayed. The coatings were subjected to turning, burnishing. The evaluation of corrosion properties were based on the measurements of corrosion current density and corrosion potential (polarization method), the charge transfer resistance and exponent of constant phase element impedance (electrochemical impedance spectroscopy method). Corrosion tests were performed in replacement seawater (3.5% sodium chloride solution). On the basis of studies, the effect of finishing type on the corrosion properties of plasma sprayed coatings has been demonstrated. The lowest corrosion current density was found for Ni-5% Al coatings after burnishing, icorr value equal to 0.96 A/cm2, and the charge transfer resistance was 27007 Ωcm2. The lowest resistance to corrosion of turned Ni-5%Al-15%Al2O3 composite coatings was observed. These coatings were characterized by the following parameters of corrosion process: icorr = 17.64 A/cm2, Rct = 2137 Ωcm2. Burnishing caused increased corrosion resistance of coatings. Due to reduced roughness and waviness are obtained reduction of the area of the actual burnished coatings compared to turned coatings. Thus, it is resulting in reduced values of corrosion current density. After finishing treatment, the plasma sprayed Ni-5%Al-15%Al2O3 coatings characterized by lower corrosion resistance compared to the alloy coating. The presence of the reinforcing phase in the coating promotes the increase of the porosity. The plasma sprayed coatings on nickel matrix had a tendency to localized corrosion in sodium chloride solution.
Źródło:
Journal of KONES; 2014, 21, 1; 273-280
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Early detection of fatigue cracks in turbine aero - engine rotor blades during flight
Autorzy:
Szczepanik, R.
Powiązania:
https://bibliotekanauki.pl/articles/245961.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
aero-engines
diagnostic of aircraft engine
non-contact blade-vibration measurement
damage to the aircraft
Opis:
The author shows results of research done in the Air Force Institute of Technology concerning design, development and implementation of modern diagnostic systems for aero-engines. The papers gives brief description of a project of a new advanced monitoring system basing on non-contact blade-vibration measurement. Recent monitoring systems for engines offer a great potential to reduce the high maintenance costs of aircraft while increasing reliability and safety. These systems check for abnormal engine responses to detect failures, saving lives and reducing secondary damage to the aircraft. A phenomenon of dynamic change of an aero-engine compressor blades natural frequency in course of fatigue cracks propagation in their roots on the example of a Polish turbojet engine is described. On the ground of this phenomenon main working principles of a device, which measures vibrations of turbine engine rotor blades with application of the noninterfering discrete method (MDPh), used for early detection of first stage compressor blade cracks are discussed. Typical representation of the first stage compressor blades vibration during engine acceleration, representation of the first stage blades vibration during engine acceleration and deceleration with steady-state stator distortions, crack initiation and propagation symptoms in blades, comparison of blade vibration spectra of the same blades for different conditions are presented in the paper.
Źródło:
Journal of KONES; 2013, 20, 1; 337-342
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Texture of surface of coatings obtained using the "Casto-Dyn 8000",torch, after burnishing treatment
Autorzy:
Starosta, R.
Powiązania:
https://bibliotekanauki.pl/articles/245991.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
flame spraying
burnishing
Ni-Al coating
Ni-Al-Al2O3 coating
torque pump
Opis:
The flame sprayed coatings are characterized by porosity, oxide inclusions presence and large real area of surface. In order to obtain adequate surface roughness coatings must be applied finishing. For this purpose, the turning and grinding are used. In the paper a burnishing to finishing flame sprayed coatings was proposed. Burnishing is not used during the processing of thermally sprayed coatings, as is commonly believed that this technology causes damage to coatings. The process of flame sprayed is a technology affordable and easy to implement. It does not require great skill of the operator. This method is not associated with expensive workstation equipment. It may therefore be used with success for the regeneration of machine parts by the crew of vessel engine room. Coatings of Ni-5% Al and Ni-5%Al-15%Al2O3 obtained by powder flame spraying were studied. Torch of "Casto-Dyn 8000" was used. After turning the average value of surface coatings roughness coefficient Ra =2.59 mi m (for Ni- 5%Al) mi m and Ra = 3.1mi m (for composite coating) was obtained. SRMD burnishing tool produced by "Yamato" company was used. Roller burnishing was performer on turning lathe. It was found that the increase in burnishing force and the reduction of burnishing speed and feed rate of less roughness of coatings are obtained. For Ni-5%Al coatings the lowest surface roughness, Ra = 0.3mi m was obtained after burnishing with the following parameters: the force - 1100 N, burnishing speed - 28m/min, feed - 0.08 mm/rev. During burnishing of Ni-5% Al-15% Al2O3 coatings applied force 700 N, Ra = 1.31 mi m was obtained. Greater burnishing force caused coatings damage. Burnishing compared to turning has positive influence on the curve shape of the material ratio. It was found that the parameters Rk and Rpk were reduced.
Źródło:
Journal of KONES; 2011, 18, 3; 413-420
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flame spraying "Roto-Teck 80" of Ni-Al and Ni-Al-Al2O3 coatings surface texture after roller burnishing
Autorzy:
Starosta, R.
Powiązania:
https://bibliotekanauki.pl/articles/246267.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermal spay coatings
burnishing
roughness
material ratio
torque pump
Opis:
The process of flame sprayed is a technology affordable and easy to implement. It does not require greats kill of the operator. This method is not associated with expensive workstation equipment. It may the refore be used with success for the regeneration of machine parts by the crew of vessel engine room. Flame spray ed coatings are characterized by porosity, oxide inclusions presence and large real area of surface. In order to obtain adequate surface roughness coatings must be applied finishing. For this purpose, the turning and grinding are used. In the paper a burnishing to finishing flame sprayed coatings was proposed. Burnishing is not used during the processing of thermally sprayed coatings, as is commonly believed that this technology causes damage to coatings. Coatings of Ni-5% Al and Ni-5%Al-15%Al2O3 obtained by powder flame spraying were studied. Torch of "Roto-Teck 80" was used. After turning the average value of surface coatings roughness coefficient Ra = 3 mi m was obtained. SRMD burnishing tool produced by "Yamato" company was used. Roller burnishing was performer on engine lathe. It was found that the increase in burnishing force and the reduction of burnishing speed and feed rate of less roughness of coatings are obtained. For Ni-5%Al coatings the lowest surface roughness, Ra = 0.3 /mi m was obtained after burnishing with the following parameters: the force - 1100 N, rate - 28m/min, feed - 0.08 mm/rev. During burnishing of Ni-5% Al-15% - A12O3 coatings applied force 700 N, Ra = l pm was obtained. Greater burnishing force caused coatings damage. Burnishing compared to turning has positive influence on the curve shape of the material ratio. It was found that the parameters Rk, Rpk and Rpk were reduced.
Źródło:
Journal of KONES; 2010, 17, 4; 477-484
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Firefighting systems in military vehicles
Autorzy:
Sosnowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/247605.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
firefighting system
military vehicle
optical and thermal sensors
steering devices
firefighting equipment
Opis:
The article discusses the examples of fire causes in the military vehicles and the consequences they may cause in the military vehicles. It has been observed that the frequent cause for the damage of military vehicles and loss of crew health and life is not the direct impact with the missile, but fires caused e.g. by impact with a missile, mines and firing bottles actions. Therefore, there is the need to use firefighting systems in the military vehicles. The development of the firefighting systems earmarked for the military vehicles has been presented. The contemporary construction solutions for the firefighting system earmarked for the motor and combat departments, as well as selected external parts of the military vehicles as well as basic conditions influencing the firefighting systems of various purposed have been discussed. The advantages and disadvantages of halons used previously as basic extinguishing means, current legal restriction concerning the halon use as well as potential halon equivalents to extinguish fires in the military vehicles have been discussed. The new extinguishing equipment, the means of which will not have negative impact on the crew, vehicle and natural environment – in particular in terms of destroying ozone layer and causing greenhouse effect will require checking the correctness of their functioning, the extinguishing effectiveness and the impact on the natural environment. The testing of the firefighting systems for military vehicles has been already conduced in the Military Institute of Armoured and Automotive Technology in Sulejówek.
Źródło:
Journal of KONES; 2015, 22, 1; 289-298
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and analysis of jet engine with cooling turbine
Autorzy:
Jakubowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/247838.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
jet engine
modelling of jet engine
modelling of jet engine with cooling turbine
Opis:
The problems of the turbojet engines with a cooling turbine modelling are discussed in the paper. The cooling systems of the contemporary jet engines are briefly described in the first part of the paper. Than the models of various turbine, cooling systems are presented and discussed. The main scope of the paper is the turbine cooling system consisted of internal convection cooling and external film cooling of turbine blades. This cooling system is commonly used in contemporary military and civil turbojet engines. The model of the internal-external cooling turbine incorporated in the overall jet engine model is presented and discussed. Some simplifying assumptions are discussed. Then the results of the jet engine calculation taking into account the proposed model are presented in the tables. The results are compared with results obtained by simple model of the jet engine with cooling turbine. The simple model is commonly applied for 1D turbojet engine analysis. Based on this analysis, some aspects of the turbojet engine calculation with reference to different models applied for description of the turbine cooling process are presented and discussed. The analysis allowed formulating some conclusions, which are presented in the final part of the paper. One of them is that proposed model of cooling turbine allows to calculate of coolant mass flow, while the simple models of cooling turbine require the assumption of coolant mass. By this way the calculation results accuracy by the use of simple model, strictly depend on the proper assumption of coolant mass flow.
Źródło:
Journal of KONES; 2012, 19, 2; 235-243
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technical and economic analysis of various solutions of fuel supply systems in marine diesel engine of ships sailing in the control emission areas (ECA)
Autorzy:
Krakowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/247954.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
environmental protection
sulphur compounds
power engines
marine scrubbers
shipping
Opis:
In the article, legal norms regarding the reduction of sulphur content limits in exhaust gases in special areas were presented. Then an overview of various solutions for supplying the marine engine with heavy fuel, distillation fuel and gas was made. In addition, the problem of using low-sulphur fuels in internal combustion engines was described. The presented solutions are a response to the latest provisions being part of the VI Annex of the MARPOL Convention, which entered into force on 01.01.2015. These provisions constitute that sulphation of fuel used in Emission Control Areas (ECAs) may not exceed 0.1%. Then, to meet the requirements, the conditions of using heavy fuels for supplying diesel engines were presented. Individual solutions such as the use of low-sulphur fuels, exhaust gas scrubber assembly, and the supply of liquefied natural gas (LNG) from the technical side were shown. Besides, the advantages and disadvantages of each of them were also indicated. In the following part, the economic analysis of the selected ship was made. Its purpose was to evaluate economically in the assumed time of operation, and then select the optimal solution for a given unit. For the comparative analysis, the use of low-sulphur fuels was used; the assembly of the scrubber, as well as the adaptation of the unit to use liquefied natural gas (LPG). The article was finished with conclusions; the most important of them is that the use of fuels with reduced sulphur content is the most expensive solution for the selected ship. The cost of the remaining solutions is at a comparable level, but they require greater interference in the ship’s construction.
Źródło:
Journal of KONES; 2018, 25, 4; 207-216
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of burnishing on surface texture of Ni - Al plasma sprayed coatings
Autorzy:
Starosta, R.
Powiązania:
https://bibliotekanauki.pl/articles/247985.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
plasma spraying
burnishing
Ni-Al coating
torque pump
Opis:
The purpose of this study was the selection of roller- burnishing parameters of surface Ni-Al coatings obtained by "PN 120" plasma torch. Coatings with low surface roughness could be applied as layers increase the service life of torque pumps shaft used on vessels in the sea water systems. After turning, the average surface roughness of plasma sprayed Ni-5% Al coatings was Ra = 0.77 mi m. Their average hardness was equal to the 253 HV 2. It was comparable to the hardness of flame sprayed Ni-Al coatings after the burnishing. Before machining, plasma sprayed alloy coatings were characterized by hardness 206 HV 2. After pre-treatment, plasma sprayed Ni-Al coatings were burnishing. Burnishing parameters were as follows: Vn=28.26 m/min, Fn=1100N, fn=0,08m/rev. Burnishing reduces the surface roughness of coatings as compared to machining. The arithmetical mean deviation of the assessed profile of machined coatings was 0.78 mi m. After the plastic working, the Ra parameter was reduced to a value of 0.28 mi m. Total height of profile of machined coatings was only 2.63 mim. After burnishing, the value of Wt decreased by 0.16 mi m, to the value of 2.47 mi m. Studies burnished surface topography of coatings of Ni-5% Al overlaid by "PN 120" torch revealed the presence of defects stereometric structure. There is the folding. These folding are arranged in the direction of peripheral velocity vector. The observed high folding on the surface of alloy coatings sprayed by plasmatron were lower from the same geometric structure defects on the surface of coatings obtained by flame spraying methods. This follows from the fact that the plasma coating, after turning, characterized by higher hardness of the sprayed coating obtained by and "Roto-Teck 80" method. Thus, exhibit a lower propensity for plastic deformation. After plastic working of plasma coatings, decrease of parameters of the material ratio curve values were observed. For example, the reduced peak height of cut coatings were 1.38 mi m, after burnishing Rpk value fell to 0.23 mi m.
Źródło:
Journal of KONES; 2012, 19, 1; 377-384
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of susceptibility to icing of aircraft piston engine Rotax 447 UL SDCI9
Badania podatności na oblodzenie lotniczego silnika tłokowego ROTAX 447 UL SCDI
Autorzy:
Chachurski, R.
Powiązania:
https://bibliotekanauki.pl/articles/248075.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
lotnictwo
zespoły napędowe
silniki tłokowe
bezpieczeństwo lotu
oblodzenie układów dolotowych
aviation
power plants
piston engines
safety of flights
induction icing
Opis:
Icing of aircrafts and their powerplants is essential danger for safety off lights and is at the bottom of many more or less serious aviation incidents and accidents in Poland and worldwide. Icing of induction systems of aircraft piston engines is caused by water contained in the air, by vapour of water contained in the air and by fuel vaporising. Experimental investigations of the temperature changing in characteristic points of induction systems of piston engine Rotax 447 UL SDCI equipped with slide carburettor BING 54/36, which have been made in the Institute of Aviation Technology of Military University of Technology, show that these temperatures strongly depend on the inlet flow conditions and are significantly below the ambient air temperature. Results of measurements, which have been made in different conditions, show that the temperature in induction systems may drop up to 16-31oC compared to the external air temperature. This high temperature drop is caused mainly by process of vaporising fuel sprayed to the carburettor. Effects of acceleration of the air in the carburettor Venturi or between the throttle and carburettor walls are minor. Similar results have been obtained for the carburettor Walbro WB-37 with butterfly throttle and for the carburettor CVK-50 with variable Venturi and butterfly throttle. No induction icing has been observed, despite severe icing potential appropriate icing risk diagram.
Oblodzenie statków powietrznych i ich zespołów napędowych stanowi istotne zagrożenie dla bezpieczeństwa lotów i jest przyczyną wielu bardziej lub mniej zdarzeń i wypadków lotniczych w Polsce i na świecie. Oblodzenie układów dolotowych lotniczych silników tłokowych jest wynikiem oddziaływania wody i pary wodnej zawartej w powietrzu atmosferycznym oraz, przede wszystkim, odparowywania paliwa. Przeprowadzone w Instytucie Techniki Lotniczej Wojskowej Akademii Technicznej badania rozkładu temperatury w charakterystycznych punktach układu dolotowego silnika tłokowego Rotax 447 UL SDCI wyposażonego w gaźnik BING 54/36 z przepustnicą tłokową pokazały, że temperatury te są znacznie niższe od temperatury otoczenia. Wyniki pomiarów przeprowadzanych w różnych warunkach pokazują, że temperatura w układzie dolotowym tego silnika spada o 16-31oC w stosunku do temperatury powietrza. Tak duży spadek temperatury jest przede wszystkim wynikiem odparowywania paliwa zasysanego z rozpylaczy do kanału przepływowego gaźnika. Wpływ przyspieszania strumienia powietrza w gardzieli gaźnika i między ściankami przepustnicy a ściankami kanału przepływowego jest znacznie mniejszy. Podobne wyniki uzyskano dla innych przebadanych gaźników: Walbro WB-37 z przepustnicą uchylną i podciśnieniowego gaźnika CVK-50. W trakcie badań nie zaobserwowano objawów oblodzenia układu dolotowego silnika, mimo, iż zgodnie z diagramem służącym do określania zagrożenia oblodzeniem, warunki były sprzyjające.
Źródło:
Journal of KONES; 2008, 15, 3; 59-66
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the ice protection systems of aircraft gas turbine engines
Analiza sposobów zabezpieczania lotniczych silników turbinowych przed oblodzeniem
Autorzy:
Chachurski, R.
Powiązania:
https://bibliotekanauki.pl/articles/241705.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
lotnictwo
zespoły napędowe
bezpieczeństwo lotu
oblodzenie
instalacje przeciwoblodzeniowe
aviation
power plants
safety of flights
icing
anti-icing system
Opis:
Icing of aircrafts and their powerplants is essential danger for safety of flights and is at the bottom of many more or less serious aviation incidents and accidents in Poland and worldwide. Icing of aircraft turbojet, turbofan, turboprop and turboshaft engines may occur not only at negative temperatures of air but at positive temperatures too. Ice detectors of anti-icing systems of aircrafts are located on airframes, mainly in front of a fuselage, on upper surface of wings or under its and do not detect of gas turbine engines icing early enough. The manual turning on of anti-icing system of engine is necessary. Icing of aviation gas turbine engines is at the bottom of mechanical damaging of blades and vanes, stall and surge of compressors, flameout, roll-back or shut down of engines by control systems. There is mechanical, pneumatical, electrical and mixed ice protection systems used in turbojet, turbofan, turboshaft and turboprop engines for their protection against icing. Hot air ice protection systems are mainly used in turbojets and turbofans. These systems are supplied by air from high pressure compressor. These kind of ice protection systems do not operate in all offlight conditions because of severe danger thrust or power reduction due to a recirculating of air in the hot air ice protection system. However, usually anti-icing systems protect engines effectively; accidents and incidents are caused by errors of crew and ground personnel members mainly.
Oblodzenie statków powietrznych i ich zespołów napędowych stanowi istotne zagrożenie dla bezpieczeństwa lotów i jest przyczyną wielu bardziej lub mniej zdarzeń i wypadków lotniczych w Polsce i na świecie. W odróżnieniu od płatowca oblodzenie lotniczych silników turbinowych może zachodzić już w dodatnich temperaturach otoczenia. Czujniki instalacji przeciwoblodzeniowych rozmieszczane są na płatowcach, głównie w przedniej części kadłuba, na górnej powierzchni skrzydeł lub pod nimi, a nie ma ich we wlotach silników, co nie umożliwia odpowiednio wczesnego wykrycia oblodzenia elementów silników, w związku z czym wymagane jest ręczne włączanie instalacji przeciwoblodzeniowych silników. Oblodzenie lotniczych silników turbinowych jest przyczyną mechanicznych uszkodzeń łopatek, niestatecznej pracy sprężarki, a nawet do samoczynnego wyłączenia się silnika lub wyłączenia go przez układ sterowania. W celu zabezpieczenia lotniczych turbinowych silników odrzutowych, śmigłowych i śmigłowcowych przed oblodzeniem stosuje się mechaniczne, powietrzne, elektryczne i mieszane instalacje przeciwoblodzeniowe. W silnikach odrzutowych najczęściej wykorzystywane są cieplne instalacje zasilane gorącym powietrzem pobieranym ze sprężarki wysokiego ciśnienia. Instalacje tego rodzaju nie mogą pozostawać włączone we wszystkich fazach lotu, ponieważ np. pobieranie powietrza ze sprężarki do instalacji przeciwoblodzeniowej obniża ciąg lub moc silnika. Działanie tych instalacji zazwyczaj jest skuteczne, a wypadki i katastrofy spowodowane oblodzeniem silników jest zwykle wynikiem błędów popełnianych przez załogi lub członków personelu naziemnego.
Źródło:
Journal of KONES; 2008, 15, 4; 81-88
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of burnishing on the contact fatigue of regenerative thermally sprayed coatings
Autorzy:
Starosta, R.
Powiązania:
https://bibliotekanauki.pl/articles/241885.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
thermal spraying
Ni-5%Al-Al2O3 coatings
contact fatigue
Opis:
This study of the resistance to contact fatigue of Ni-5%Al alloy coatings and Ni-5%Al-15%Al2O3 composite coatings were evaluated. The coatings were prepared by flame spraying (Casto-Dyn DS 8000 torch) and plasma spraying (PN 120 plasma jet). The coatings were subjected to a finishing treatment: turning, burnishing and grinding. Depending on coatings phase composition and finishing treatment, the parameter mean values of surface roughness (Ra) were in the wide range of 0.28 to 2.61 m. The coatings after burnishing characterized by smallest of surface roughness. The largest value of the parameter Ra was observed in the case of coatings after turning. The presence of the reinforcing phase in the coating increases the surface roughness of thermally sprayed composite coatings. The hardness of coatings also depends on the finishing methods. The minimum hardness equal to 192 HV2 was found in the case of coatings of Ni-5%Al obtained by using a Casto-Dyn DS 8000 gas torch. Burnished Ni-5%Al-15%Al2O3 coatings obtained by plasma spraying characterized by hardness 291 HV2. Resistance of fatigue surface of thermally sprayed coatings on a SCF (standing contact fatigue) test stand was assessed. The test was designed based on the guidelines of the PN-80/H-04324 Polish standard. During the fatigue tests were provided constant contact of co-acting parts, without slipping. Based on the survey it was found that the plasma sprayed coatings (PN120 plasma-jet) have a greater resistance to fatigue then the coatings obtained by flame spraying Casto-Dyn DS 8000 torch. Composite coatings of Ni-5%Al- 15%Al2O3 are more resistant to contact fatigue, compared to the alloy coatings of Ni-5%Al. Burnishing increases the fatigue resistance of coatings when compared to turning. Burnished and polished surfaces are characterized by a similar contact fatigue resistance.
Źródło:
Journal of KONES; 2013, 20, 1; 309-315
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-combustor turbofan engine performance analysis
Autorzy:
Jakubowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/241903.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
jet engine
turbofan engine
engine performance
airplane engine development
Opis:
A conception of a two-combustor turbofan engine is the main scope of this paper. At the beginning, the problems of turbofan engines development are briefly discussed as a background of this work. In this part the turbofan engines innovation activities are presented. It is mentioned the engine’s innovations consists of many aspects but some important ones are: lowering of production operation cost, maintenance, reduction of noise and exhaust gases emission while engine reliability should stay on the same level or event increase. Next, the conception of turbofan engine with two combustors is presented in this context. Some positive aspects for environment, production and maintenance of such engine are discussed. Then the thermodynamic cycle of two-combustor engine is presented and analysed. On this basis, the engine numerical model is prepared. Next, some information about the model simplifications and calculations done to determine performance of the engine is presented. Then the results of the simulation calculations of the engine performance are presented and discussed. The relationship of engine thrust and specific fuel consumption vs. engine flight conditions are shown. Based on the results there were discussed the advantages and disadvantages of two combustors engine as an airplane propulsion are specified. The conclusions are formulated and presented in the last part of the paper.
Źródło:
Journal of KONES; 2014, 21, 3; 141-148
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Internal combustion engine cooling system with elevated coolant temperature research on the model test stand
Autorzy:
Krakowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/242843.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
engine cooling
test stand
coolant temperature
Opis:
In the paper a model test stand designed and built using original components of diesel engine 4CT90 is presented. The stand provides working conditions as close as possible to the exploitation conditions of the engine cooling system. This applies both to the intensity of heat inside the cylinders of the engine, the temperature uniformity along the cylinder axis, as well as variable-speed water pump. Research carried out on the model stand were aimed at checking the operation of the cooling intensity control with varying levels of filling of the cooling system and develop a control method of the cooling system before testing on the dynamometer stand. In addition, system operation at elevated cooling liquid pressure for the possibility of obtaining the elevated coolant temperature were checked. The influence of working conditions on the level of the temperature was also analysed. In this paper, the characteristics selected for two values of pressure, for 0.15 MPa and 0.2 MPa, and for two different values of the degree of filling of the cooling liquid were presented. During the warming-up and continuous heating of the cylinder and the cylinder head by electrical heaters, temperature and overpressure courses before and after the liquid radiator, temperature before the inlet and outlet of the liquid from the engine and the temperature at selected points inside the engine water jacket are designated. The results of measurements of the coolant pump flow at different speed water pump were also presented in this paper.
Źródło:
Journal of KONES; 2013, 20, 4; 177-183
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł

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