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  1. 8 Combustion Engines
  2. 5 Journal of KONES
  3. 5 Rudy i Metale Nieżelazne
  4. 4 Proceedings of the Institute of Vehicles
  5. 4 Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska
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  1. 6 Lubikowski K.
  2. 5 Nowak S.
  3. 5 Szczurowski K.
  4. 5 Żaba K.
  5. 4 Radkowski S.
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  1. 1 2023
  2. 3 2021
  3. 1 2020
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  5. 4 2018
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1
Content available Analysis of the combustion engine exhaust system structure in aspect of shaping acoustic energy
Gągorowski Andrzej
Combustion Engines
|
2023
|
R. 62, nr 2
112--116
EN
The flow of exhaust gases is the source of many physical processes, including thermal, acoustic, mechanical and chemical phenomena with high dynamics of changes. The study analyzes the impact of the entire structure of the exhaust system on the formation of acoustic energy, determining the transmission loss characteristics of its individual components and the entire system. On the example of a structure based on a proprietary solution of an adjustable reactive muffler, the possibilities of shaping the flow of acoustic waves in the process of designing and selecting exhaust systems for internal combustion engines were determined. The study was carried out with the use of the CFD method and a specialized package for advanced simulations AVL AST.
2
Content available Projekt stanowiska do spawania elementów tłumika samochodowego
Temel Wojciech, Czajka Ireneusz, Lach Tomasz, Halama Łukasz
Mining – Informatics, Automation and Electrical Engineering
|
2021
|
R. 59, nr 3
56--60
PL
Wykonywanie dużych partii powtarzających się elementów stanowi wyzwanie dla ręcznego procesu spawania. Rozwiązaniem tych problemów jest automatyzacja z wykorzystaniem maszyn o układach dwu- lub wieloosiowych. Projekt stanowiska do spawania elementów tłumika samochodowego skupia się na automatyzacji jednego z procesów produkcji w firmie Ulter-Sport Sp. z o.o. dzięki wykorzystaniu prototypowego pięcioosiowego stanowiska sterowanego numerycznie. Zastosowanie tego rodzaju rozwiązania daje operatorowi możliwość szybkiego opracowania nowych cykli spawania, które za pomocą układu śrub kulowych oraz silników krokowych są wielokrotnie i dokładnie odtwarzanie. Przestronne pole robocze oraz duże możliwości ruchu głowicy spawalniczej pozwalają na adaptację maszyny do wykonywania innych zadań bazujących na spawaniu.
EN
Making large batches of repeatable components is a challenge for the manual welding process. The solution to these problems is automation using machines with two- or multi-axis systems. The design of a station for welding elements of car mufflers focuses on the automation of one of the processes at Ulter-Sport Sp. z o.o. through the use of a prototype five-axis numerically controlled station. The use of this type of solution provides the operator with the opportunity to quickly develop new welding cycles, which are repeatedly and accurately mapped using a ball system and stepper motors. The spacious working area and large movement capabilities of the torch allow the machine to adapt to perform other welding tasks.
3
Content available Design of a station for welding parts of a car exhaust system
Temel Wojciech, Czajka Ireneusz, Lach Tomasz, Halama Łukasz
Mining – Informatics, Automation and Electrical Engineering
|
2021
|
R. 59, nr 3
51--55
EN
Making large batches of repeatable components is a challenge for the manual welding process. The solution to these problems is automation using machines with two- or multi-axis systems. The design of a station for welding elements of car mufflers focuses on the automation of one of the processes at Ulter-Sport Sp. z o.o. through the use of a prototype five-axis numerically controlled station. The use of this type of solution provides the operator with the opportunity to quickly develop new welding cycles, which are repeatedly and accurately mapped using a ball system and stepper motors. The spacious working area and large movement capabilities of the torch allow the machine to adapt to perform other welding tasks.
PL
Wykonywanie dużych partii powtarzających się elementów stanowi wyzwanie dla ręcznego procesu spawania. Rozwiązaniem tych problemów jest automatyzacja z wykorzystaniem maszyn o układach dwu- lub wieloosiowych. Projekt stanowiska do spawania elementów tłumika samochodowego skupia się na automatyzacji jednego z procesów produkcji w firmie Ulter-Sport Sp. z o.o. dzięki wykorzystaniu prototypowego pięcioosiowego stanowiska sterowanego numerycznie. Zastosowanie tego rodzaju rozwiązania daje operatorowi możliwość szybkiego opracowania nowych cykli spawania, które za pomocą układu śrub kulowych oraz silników krokowych są wielokrotnie i dokładnie odtwarzanie. Przestronne pole robocze oraz duże możliwości ruchu głowicy spawalniczej pozwalają na adaptację maszyny do wykonywania innych zadań bazujących na spawaniu.
4
Content available Bench Tests for Exhaust Gas Temperature Distribution in an Aircraft Piston Engine with and without a Turbocharger
Czarnigowski Jacek Andrzej, Skiba Krzysztof, Rękas Daniel, Ścisłowski Karol, Jakliński Piotr
Advances in Science and Technology. Research Journal
|
2021
|
Vol. 15, no 3
155--166
EN
In ultralight aviation, a very important engine parameter is the power-to-weight ratio. On the one hand, there is a tendency to minimize the size and weight of engines, and on the other hand, there is a demand to achieve the highest possible power by using supercharging systems. Increasing power brings many benefits, but it also increases temperature in the exhaust system, posing a threat to delicate parts of the ultralight aircraft fuselage. Therefore, it is necessary to control temperature values in the engine exhaust system. This article presents the temperature distribution in the exhaust system of an aircraft engine by the example of a four-cylinder Rotax 912 engine with an electronic fuel injection system. The research was conducted in two stages: measurements were made first for the engine without a turbocharger with an original exhaust system and later for its modified version with an added turbocharger system. The paper presents a comparative analysis of exhaust gas temperatures measured at three points: 30, 180 and 1000 mm from the cylinder head. The tests were conducted for the same preset engine operating conditions at constant speed and manifold air pressure. It has been shown that the exhaust temperature in the exhaust manifold decreases with the distance from the cylinder head. The highest gradient, over three times higher than the gas temperature from 589.9 °C to 192.3 °C, occurred in the manifold with a turbocharger for 2603 RPM and 31 kPa of manifold air pressure. The introduction of turbocharging causes an increase in exhaust gas temperatures before the turbocharger by an average of 12%, with this increase being greater for operating points of higher inlet manifold pressure. Turbocharging also causes a significant decrease in exhaust gas temperatures behind the turbocharger and the silencer because the temperature drops there by an average of 25%.
5
Content available Fluid dynamic and acoustic optimization methodology of a formula-student race car engine exhaust system using multilevel numerical CFD models
Mohamad Barhm, Ali Mohammed Qasim, Neamah Hayder Ahmed, Zelentsov Andrei, Amroune Salah
Diagnostyka
|
2020
|
Vol. 21, No. 3
103--111
EN
In this work a multilevel CFD analysis have been applied for the design of an engine exhaust system include manifold and muffler with improved characteristics of noise reduction and fluid dynamic response. The approaches developed and applied for the optimization process range from the 1D to fully 3D CFD simulation, exploring hybrid approaches based on the integration of a 1D model and 3D tools. Once the best configuration has been defined, the 1D-3D approach has been adopted to confirm the prediction carried out by means of the simplified approach, studying also the impact of the new configuration on the engine performances.
6
Influence of material heat treatment on low cycle fatigue of austenitic steel at working conditions of gas turbine exhaust structures
Zielaskowski Michał, Bielecki Marcin, Pawlicki Jakub
Inżynieria Materiałowa
|
2019
|
Vol. 40, nr 5
111--119
EN
The paper presents a statistical analysis based on more than 500 fatigue tests available in the scientific literature, for which the influence of thermal treatment of austenitic steel on the low-cycle life of gas turbine exhaust elements is shown. The confidence range of regression parameters for test data is shown and an analysis of variance for different groups of parameters was carried out. Conducted statistical analysis allows to select important parameters affecting the life of the material, while allowing to reject non-essential parameters, which in effect allows correct description of the phenomenon. The collected data from fatigue tests was limited to those whose parameters correspond to the typical work conditions of gas turbine exhaust elements. The tested material is austenitic steel type AISI240 TP304 in various states of heat treatment: aging, tempering and in an as-fabricated condition. The tests were carried out in isothermal conditions with a fast-changing cycle or a cycle with tensile load hold during stretching.
PL
W pracy zaprezentowano analizę statystyczną wykonaną na podstawie ponad 500 wyników prób zmęczeniowych dostępnych w literaturze naukowej, dla których pokazano wpływ obróbki cieplnej stali austenitycznej na trwałość niskocyklową stali austenitycznej. Przeprowadzono analizę regresji dla zgromadzonych danych oraz analizę wariancji dla różnych grup parametrów obróbki cieplnej. Przeprowadzona analiza statystyczna pozwala na wyselekcjonowanie istotnych parametrów wpływających na trwałość materiału, pozwalając jednocześnie odrzucić parametry nieistotne, co w efekcie pozwala na poprawne opisanie zjawiska. W pracy ograniczono użyte dane do odpowiadających typowym parametrom pracy elementów odprowadzających spaliny w turbinach gazowych.
7
Content available Identification of surface stress in the exhaust system pipe made by hydroforming technology based on diffractometric measurements
Kucharska Barbara
Eksploatacja i Niezawodność
|
2019
|
Vol. 21, no. 4
562--566
EN
In the work identificaton of surface stresses in the exhaust pipe made of Cr-Ni steel shaped with hydroforming technology. Stresses were determined by the non-destructive x-ray method sin2ψ. A complex state of tensile stresses with values in the range of 69÷240 MPa for circumferential stresses and 26÷290 MPa for longitudinal stresses was found on the surface of the pipe. The distribution of stresses on the circumference and length of the pipe was analyzed on the basis of coefficients of variation and wall thickness. A relationship was found between the value of surface stress and the wall thickness of the pipe. The highest stresses occurred in the areas of the pipe where the thickness of the wall was reduced the most. In the central part of the pipe, where the wall thickness reduction was the smallest, the stresses were also the smallest, but they were characterized by the highest dispersion of value. The distribution of surface stresses determined by diffractometric method was compared with the model of deformation of the pipe generated numerically.
PL
W pracy dokonano identyfikacji naprężeń powierzchniowych w rurze wydechowej ze stali Cr-Ni kształtowanej technologią hydroformowania. Naprężenia wyznaczono nieniszczącą rentgenowską metodą sin2ψ. Na powierzchni rury stwierdzono złożony stan naprężeń rozciągających o wartościach z zakresu 69÷240 MPa dla naprężeń obwodowych i 26÷290 MPa dla naprężeń wzdłużnych. Rozłożenie naprężeń na obwodzie i długości rury analizowano na podstawie współczynników zmienności i grubości ścianki. Stwierdzono zależność pomiędzy wartością naprężeń powierzchniowych a grubością ścianki rury. Największe naprężenia występowały w obszarach rury gdzie grubość ścianki była najsilniej zredukowana. W centralnej części rury gdzie redukcja grubości ścianki była najmniejsza naprężenia również były najmniejsze, ale cechowały się największym rozproszeniem wartości. Rozłożenie naprężeń powierzchniowych wyznaczonych metodą dyfraktometryczną porównano z modelem odkształceń w rurze wygenerowanym numerycznie.
8
Content available The potential of thermoelectric energy harvesting in vehicles equipped with ICE
Buchalik Ryszard, Rogozinski Krzysztof, Nowak Grzegorz
Combustion Engines
|
2019
|
R. 58, nr 4
70--74
EN
The paper deals with an issue of waste heat recovery in a selected configuration of an internal combustion engine. A possibility of using thermoelectric cells (currently available on the market) for production of electricity with heat extracted from the exhaust gas was considered. The calculations were made using specialized software. Features and design assumptions of the heat recovery system were presented and their influence on parameters of the entire system was investigated (efficiency of the internal combustion engine, power, etc.). An assessment of the applicability of the energy recovery system based on thermoelectric effects and characteristic of the proposed configuration was performed. Some issues that require further research have been highlighted.
9
Content available Investigations of the temperature distribution in the exhaust system of an aircraft piston engine
Czarnigowski Jacek, Skiba Krzysztof, Dubieński Kamil
Combustion Engines
|
2019
|
R. 58, nr 2
12--18
EN
Ultralight aviation is based on piston engines requiring both performance and reliability. An important aspect is also the requirements for the installation of such an engine on an airframe, especially its heat emission. This is firstly because of the need to ensure proper engine cooling and secondly because composite elements of the airframe skin are not exposed to excessive overheating. For this purpose, bench tests of the temperature distribution of the exhaust system of ROTAX 912 engine were carried out. Measurements were taken at 6 points of the exhaust system, where the temperature of the exhaust gases and exhaust pipes were measured. The tests covered a wide range of engine operation. The paper presents the temperature distribution at selected points in relation to the engine speed and load.
10
Content available Concept of using the heat pipes in the heat exchanger of diesel engine exhaust system intended for use in potentially explosive atmospheres
Lesiak Krzysztof, Brzeżański Marek, Prostański Dariusz
Combustion Engines
|
2019
|
R. 58, nr 2
127--131
EN
Limiting the temperature of exhaust gases to below 150°C is one of the necessary conditions for diesel engine to be used in a potentially explosive atmosphere. For this purpose heat exchangers are necessary to be used. This article presents the concept of exchanger in which heat pipes are used to transport thermal energy from the exhaust gases to the cooling medium.
11
Content available remote Badanie wybranego połączenia w układzie wylotowym z uwzględnieniem analizy akustycznej
Gągorowski A.
Prace Naukowe Politechniki Warszawskiej. Transport
|
2018
|
z. 121
57--66
PL
W artykule przedstawiono badania wybranego rodzaju połączenia układu wylotowego na przykładzie elementu o określonym kącie wygięcia, łączącego kolektor wydechowy z katalizatorem. Odwzorowano rzeczywiste rozwiązanie o strukturze cylindrycznej łukowej oraz określono wpływ parametrów krzywizny na zmiany tłumienia energii akustycznej. Modelowanie i symulacje akustycznych przepływów gazodynamicznych w układzie wydechowym oparto na specjalistycznym pakiecie obliczeniowym CFD (Computer Fluid Dynamics), mianowicie AVL AST. W celu ilościowego określenia stopnia wpływu przyjętego stopnia zakrzywienia elementu połączeniowego dokonano porównania badanej struktury z elementem prostoliniowym (z łącznikiem prostym).
EN
The article presents the research of the selected type of exhaust system connection on the example of the component with a specific bending angle and connecting the exhaust manifold with the catalyst. The actual solution with an arched cylindrical structure was modeled and the influence of curvature parameters on changes in acoustic energy attenuation was determined. Modeling and simulations of acoustic gas-dynamic flows in the exhaust system were conducted using specialized computational package CFD(Computer Fluid Dynamics), namely the AVL AST. In order to quantify the degree of influence for the assumed degree of curving of the connecting element, the structure with the rectilinear element was compared (with a straight connector).
12
Content available remote Analysis of cooling of the exhaust system in a small airplane by applying the ejector effect
Złoty Ł., Łapka P., Furmański P.
Journal of Power Technologies
|
2018
|
Vol. 98, nr 1
121--126
EN
This paper presents a thermal analysis of elements of the exhaust system of the redesigned airplane I-23. In order to improve the thermal performance of the exhaust system and decrease thermal loads inside the engine bay, modifications of the initial geometry of the cover pipe were proposed. This pipe shields the nacelle interior from thermal interaction and direct contact with the hot exhaust pipe. Several openings were created in its wall to increase the mass flow rate of the cold air sucked in from the nacelle interior to the gap between the exhaust pipe and its cover due to the ejector effect. Then numerical models were developed and simulations for flight conditions were carried out for the original and modified exhaust systems. The results obtained for both geometries were compared, showing that openings in the cover duct resulted in a high mass flow rate flowing through the gap between exhaust pipe and its cover and a lower exhaust pipe temperature. Even though the number, locations and cross-section area of the openings were selected arbitrarily, better thermal performance was obtained for the modified exhaust system.
13
Content available Parametry pracy turbodoładowanego silnika ZI samochodu osobowego w warunkach nieszczelności układu wydechowego
Hennek K., Graba M.
Autobusy : technika, eksploatacja, systemy transportowe
|
2018
|
R. 19, nr 6
463--467, CD
PL
W artykule omówiony został wpływ nieszczelności układu wydechowego na parametry użytkowe oraz emisję substancji szkodliwych w spalinach turbodoładowanego silnika o zapłonie iskrowym samochodu osobowego. Dokonano analizy porównawczej wyników pomiarów uzyskanych na hamowni podwoziowej MAHA MSR500 w warunkach szczelności oraz sztucznego wytworzenia nieszczelności układu wydechowego w miejscu montażu szerokopasmowego czujnika stężenia tlenu w spalinach. Przedstawione dane odnoszą się między innymi do emisji toksycznych i nietoksycznych składników spalin, przebiegów mocy w układzie napędowym oraz chwilowych wartości współczynnika nadmiaru powietrza. W celu uzyskania danych wykonano szereg przejazdów pomiarowych według profilu prędkości cyklu jezdnego EUDC.
EN
Paper discussed the influence of exhaust system leakage on the utility parameters and toxic combustion products emission of a turbocharged passenger car spark ignition engine. A comparative analysis of the data gathered in the research carried out using the MAHA MSR 500 single roller chassis dynamometer was conducted, where the exhaust system was sealed and leaking in the area of the wideband oxygen sensor mounting bracket. The presented data refers to among others: the emissions of harmful gasoline oxidation products (HC, CO), the courses of power generated by the engine and the momentary values of excess air ratio. The EUDC driving cycle was used in the research.
14
Content available Analysis of car waste heat recovery system utilizing thermoelectric generator
Nemś A., Simiński M., Nemś M., Magiera T.
Autobusy : technika, eksploatacja, systemy transportowe
|
2018
|
R. 19, nr 6
619--626, CD
EN
This paper presents a calculation algorithm for a thermoelectric generator fitted in the exhaust system of a combustion engine. The viability of the presented calculation method was verified on an actual combustion engine. The calculations were performed for a BMW engine, and the generator design was based on a prototype from the same manufacturer. The paper includes calculations of the thermal cycle and of the parameters of exhaust gases from the engine. Subsequent calculations cover heat transfer from exhaust gases to the thermoelectric module and the amount of electric energy obtained from a series of modules. In the last part, the focus is on the influence of engine speed on the performance of the thermoelectric generator.
PL
W pracy przedstawiono algorytm obliczeniowy generatora termoelektrycznego do zastosowania w układzie wydechowym silnika samochodowego. W celu sprawdzenia poprawności metody obliczeniowej pokazano jej przydatność na wybranym przykładzie silnika spalinowego. Do obliczeń wykorzystano silnik marki BMW, a konstrukcję generatora oparto o prototyp tej samej marki. Przeprowadzono obliczenia obiegu cieplnego i wyznaczono parametry spalin na wylocie z silnika. Następnie wykonano obliczenia przekazywania ciepła od spalin do modułu termoelektrycznego i wyznaczono energię elektryczną uzyskiwaną z szeregu modułów. W ostatniej części przedstawiono wpływ prędkości obrotowej silnika na parametry pracy generatora termoelektrycznego.
15
Content available The role and tasks of the support mats in construction of catalytic converters
Kozioł-Jarosz M., Brzeżański M.
Combustion Engines
|
2017
|
R. 56, nr 3
96--99
EN
The purpose of support mats used in catalytic converters as connecting element between the ceramic core and the metallic converter housing has been presented in article. The functional requirements and operating conditions have been discussed as well as support mat types and manufacturing methods. The support mat choice and basic design features have been also presented.
16
Content available Model of exhaust system of a traction diesel engine with pulse supercharging on transient modes
Babel M., Kossov E.
Combustion Engines
|
2017
|
R. 56, nr 1
38--45
EN
A mathematical model of joint operation of a piston engine with pulse turbine drive, compressor as well as air supply of a diesel locomotive is presented in the article. This model in an integral part of the complex engine-generator power unit of a diesel locomotive in steady states and transient conditions, developed by the authors. The periodic process in the exhaust manifold is represented as two specific characteristic ranges which encompass the process of forced exhaust and the scavenging process. The scavenging calculation is carried out jointly with the processes taking place in the inlet manifold of the engine, including inlet devices of the locomotive. The process of forced exhaust is calculated separately from the inlet processes and doesn`t require usage of empirical coefficients of impulsiveness. Both processes are represented as systems of nonlinear algebraic equations describe in the quasi-steady flow of working fluid in the elements of the inlet and exhaust tracts. The gas-dynamic calculation of the turbine in the transition process is conducted while taking into account changes in flow angles on the rotor blades. As a result of numerical calculation of the a8S22W diesel operational indices in transient modes, a satisfactory compliance of the calculated and the experimental results was obtained.
17
Content available Concept of the exhaust system of combustion engines used in underground mining
Lesiak K., Brzeżański M.
Combustion Engines
|
2017
|
R. 56, nr 2
97--100
EN
Analyses the problems occurring in the exploitation combustion engines used in mining have been presented in article. Design solutions used at present to protect the intake and exhaust systems of internal combustion engines operated in underground hard coal mines have been also described. A new design concept of exhaust system have been presented.
18
Content available Improvement of energy balance in automotive vehicle, based on combustion engine losses
Olszowiec P., Luft M., Łukasik Z.
Archives of Transport System Telematics
|
2017
|
Vol. 10, iss. 1
33--37
EN
The paper presents an innovative method to increase the overall effi ciency of the internal combustion engine. The presented method is based on the kinetic energy derived from the fl ow of exhaust gases in the exhaust system of the internal combustion engine. Th is energy is used to drive a high speed turbogenerator which is integrated with the gained energy system management. Such a system, which uses energy otherwise lost in the engine exhaust system, allows the acquisition of additional electrical energy. As a result, it improves the energy balance of a motor vehicle. Th is is particularly important in a situation of constantly expanding system of electric receivers in vehicles. Th e paper presents an analysis of the research results of the system of energy recovery, carried out on turbo supercharged engine with spark ignition. Th e article also gives the research results on the impact of the proposed system on the environment.
19
Content available The abrasion of Al-Si coatings with different silicon crystal morphology, applied in automotive silencers
Wróbel-Knysak A., Kucharska B.
Tribologia
|
2016
|
nr 5
209--218
EN
This paper compares the abrasibility of aluminium-silicon coatings with silicon crystals of various forms. The tests were performed on Al-Si coatings with the chemical composition corresponding to that of hypoeutectic and peritectic silumins (6-10wt% Si), manufactured by hot-dipping on type X2CrTi12 steel and by cold cladding with 60% cold reduction on AlMn1Cu alloy. The hot-dip coatings deposited on X2CrTi12 steel were investigated as made and after a two-stage heat treatment: 420oC/2h/water and 120oC/2h/air. The morphology, shape, and size of silicon crystals in the coatings were studied under a microscope and with the image analysis technique (determining the shape factor among other parameters). Image analysis was also applied to the evaluation of abrasive wear resistance of the coatings using a ball wear test. Their adhesion strength was tested with the scratch test method. The test results indicated that the change in Al-Si coating silicon crystal morphology (from large sharp edged and needle-like to smaller rounded particles) was heat induced, which, compared to the pre-treatment condition, lowered abrasion resistance values and produced a more uniform abrasion loss. This condition was regarded as more desirable in terms of maintaining the coating continuity during drawing, with no risk of spalling. It was also demonstrated that clad Al-Si coatings could provide an alternative solution for the widely used hot dip coatings on steel sheet.
PL
W pracy dokonano porównania ścieralności powłok aluminiowo krzemowych o zróżnicowanej formie kryształów krzemu. Badano powłoki Al-Si, o składzie chemicznym odpowiadającym gatunkom siluminów pod- i około eutektycznych (6–10% Si) wykonane metodą ogniową na stali X2CrTi12 oraz poprzez platerowanie na zimno z 60% stopniem zgniotu na stopie AlMn1Cu. Powłoki ogniowe na stali X2CrTi12 badano w stanie po otrzymaniu oraz po dwuetapowej obróbce cieplnej: 420oC/2h/woda i 120oC/2h/powietrze. W pracy dokonano oceny morfologii, kształtu i rozmiarów kryształów krzemu w powłokach metodą mikroskopową z użyciem komputerowej analizy obrazu (wyznaczając m.in. współczynnik kształtu). Analizę obrazu zastosowano również do oceny odporności na zużycie ścierne powłok przeprowadzonej kulotesterem. Dodatkowo badano ich adhezję metodą zarysowania. W wyniku badań stwierdzono, że zmiana morfologii kryształów krzemu w powłokach Al-Si spowodowana obróbką cieplną (z dużych ostrokrawędziowych i iglastych na mniejsze i o wyoblonych kształtach) spowodowała obniżenie ich odporności na ścieranie w stosunku do stanu przed obróbką, przy jednoczesnym bardziej równomiernym ścieraniu się powłok. Stan taki uznano za korzystniejszy z punktu widzenia zachowania ciągłości powłok podczas tłoczenia, bez ryzyka powstawania wykruszeń. Wykazano ponadto, że powłoki platerowane stopem Al-Si mogą stanowić alternatywę dla produkcji detali układów wydechowych w miejsce obecnie stosowanych powłok ogniowych na blachach ze stali.
20
Content available Design and optimisation of exhaust system of light turboprop airplane
Stalewski W.
Journal of KONES
|
2016
|
Vol. 23, No. 2
341--348
EN
Innovative exhaust system for light turboprop airplane has been developed and optimised. Apart from the basic function of removing exhaust from turboprop engine, the system supports cooling of the engine bay. To do this, the system removes hot air from the engine bay, utilising the ejector-pump effect, where the exhaust stream generates under-pressure, sucking the hot air through the ejector slot and removes the air together with the exhaust gases. The design and optimisation of the exhaust system has been conducted based on computational methods of Computer-Aided Design and Optimisation and Computational Fluid Dynamic. Three-dimensional analysis of flow around the airplane (including effect of propeller) and inside the exhaust system was conducted by application of URANS solver ANSYS FLUENT. Using these software the trajectories of exhaust particles, both inside the exhaust ducts and outside the airplane, have been determined. Parametric model of the designed exhaust system has been developed using the in-house software PARADES. As design parameters the diameter, length and direction of exhaust ducts as well as few parameters describing a shape of the ejector, have been established. The optimisation process aimed at designing of the exhaust system, which removes the exhaust gases possibly far away from the airframe, especially during a descent flight of the airplane. Additional objectives were maximisation of the mass flow rate of hot air sucked through the ejector and minimisation of the drag force generated by external part of the exhaust system. The optimised exhaust system should have also fulfilled requirements of permissible total-pressure losses inside the exhaust ducts. The optimised exhaust system has been implemented on the light turboprop airplane and validated during flight tests.
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