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Wyszukujesz frazę "nacelle" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Optimisation of a Nacelle Electro-Thermal Ice Protection System for Icing Wind Tunnel Testing
Autorzy:
Gallia, Mariachiara
Carnemolla, Alessandro
Premazzi, Marco
Guardone, Alberto
Powiązania:
https://bibliotekanauki.pl/articles/36810362.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
in-flight icing
ice protection systems
optimisation
genetic algorithms
nacelle
Opis:
Aircraft are equipped with ice protection systems (IPS), to avoid, delay or remove ice accretion. Two widely used technologies are the thermo-pneumatic IPS and the electro-thermal IPS (ETIPS). Thermopneumatic IPS requires air extraction from the engine negatively affecting its performances. Moreover, in the context of green aviation, aircraft manufacturers are moving towards hybrid or fully electric aircraft requiring all electric on-board systems. In this work, an ETIPS has been designed and optimised to replace the nacelle pneumatic-thermal system. The aim is to minimise the power consumption while assuring limited or null ice formation and that the surface temperature remains between acceptable bounds to avoid material degradation. The design parameters were the length and heat flux of each heater. Runback ice formations and surface temperature were assessed by means of the in-house developed PoliMIce framework. The optimisation was performed using a genetic algorithm, and the constraints were handled through a linear penalty method. The optimal configuration required 33% less power with respect to the previously installed thermo-pneumatic IPS. Furthermore, engine performance is not affected in the case of the ETIPS. This energy saving resulted in an estimated reduction of specific fuel consumption of 3%, when operating the IPS in anti-icing mode.
Źródło:
Transactions on Aerospace Research; 2023, 1 (270); 32-44
0509-6669
2545-2835
Pojawia się w:
Transactions on Aerospace Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal performance analysis of manned airships in a thermally variable environment
Autorzy:
Shi, Hong
Liu, Meinan
Chen, Jiamin
Zou, Yitao
Powiązania:
https://bibliotekanauki.pl/articles/2173708.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
manned airship
thermal performance
nacelle
temperature difference
flight position
sterowiec załogowy
wydajność cieplna
gondola
różnica temperatur
pozycja lotu
Opis:
The safety and reliability of the manned airship depend to a considerable extent on its thermal performance. In this paper, heat balance equations are developed and solved in the C++ programming language. The temperature variation of the enclosure, gasbag, and nacelles of the manned airship is investigated. In addition, the effects of season, latitude, and orientation on the thermal performance of the manned airship and the airship nacelle are investigated. The results show that: (1) The average temperature difference of the nacelle surface at the same time is 25 K, while the maximum temperature difference in the nacelle is 29 K during the day, (2) the temperature distribution in the nacelle is similar in spring and autumn, with maximum temperature between 306 K and 309 K. The maximum temperature in the nacelle is between 300 K and 303 K in winter while the maximum temperature in the nacelles is between 309 K and 315 K in summer, (3) as the flight position of the manned airship changes from 20°N to 60°N, the average nacelle temperature varies slightly by about 1 K. However, as the latitude increases, the high- temperature region shifts from the bottom of the nacelle to the side of the nacelle, and (4) the temperature distribution of the upper envelope of the airship varies considerably with orientation. However, the average temperature of the nacelle is less impacted by orientation. These results are useful for understanding the thermal performance of manned airships.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 5; art. no. e143105
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aerodynamic effect of turbo prop engine slipstream on aircraft tail assembly vibration
Autorzy:
Zalewski, W.
Stalewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/241875.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
air transport
aerodynamic wake
nacelle
tail assembly
vibration
Opis:
The article presents a computational analysis of the effect of the turboprop engine slipstream on generation of aerodynamic forces induced vibrations of aircraft tail assembly (empennage). Working propellers exhaust system, engine nacelle, and wing-engine nacelle flow interference phenomenon can cause strong non-stationary disturbances behind the wing of the aircraft. These disturbances, propagating in the direction of the aircraft tail assembly, may be an important factor influencing the operation of the airplane flow control system and the source of aerodynamic forces generating vibrations of the entire plane structure. The article presents an example of analysis of this phenomenon for a light passenger-transport aircraft using advanced numerical models for simulation of the flow around the aircraft. In the computational model, Navier-Stokes flow equations were solved by finite volume method with the K-Omega SST turbulence model to calculate the turbulent kinetic energy distribution in the flow slipstream behind the airplane propulsion unit. The Ansys Fluent commercial solver was used to run analyses. To perform the simulation, high quality, dedicated conformal computational mesh, consisting of hexahedral and tetrahedral elements was prepared to evaluate the propagation of the flow disturbances with limited numerical dispersion effect. Mesh generation was conducted using Ansys ICEM CFD and Mesher software. Unsteady aerodynamic forces for horizontal and vertical tail-planes of the airplane were computed during simulations. Fourier analysis of the driven forces was performed, which resulted in finding the dominating vibration frequencies generated by the flow field around the tail assembly. The visualization of the flow field and the regions of the strong disturbances were presented. Results can be exploited in the pre-design process of aerodynamic configuration of multi-engine aircrafts.
Źródło:
Journal of KONES; 2017, 24, 4; 363-367
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of wing-engine nacelle aerodynamic interference
Autorzy:
Zalewski, W.
Stalewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/243801.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
air transport
nacelle-wing integration
flow separation
adjoint solver
parametric design
Opis:
The article presents an analysis of the wing-engine nacelle flow interference phenomenon on the example of a light twin-engine commuter aircraft. The problems of propulsion system integration with the wing in airplanes are now frequently the subject of advanced optimization research performed by aircraft manufacturers. The shape of the engine nacelle and its connection with the wing determines the quality of the flow around the wing in that area. This is important for high-lift devices placed at the wing trailing edge behind engine nacelle used during the take-off and landing process. Additionally the flow is effected by the disturbances generated by working propellers, the presence of air inlets and an exhaust system of the engine. The article presents a process of numerical optimization of an engine nacelle rear part shape. The main goal of the process was to eliminate the flow disturbances caused by the engine nacelle-wing interference phenomenon. During analysis, the Adjoint Solver method was used to designate nacelle body areas where modification should have the most important impact on the flow quality. The results obtained from adjoint solver were used in the process of finding the optimum shape of the rear part of the nacelle using a parametric geometry generator powered by Ansys Design Modeler and PARADES software. Comparative computational analysis for selected geometries of the engine nacelle was performed using commercial Ansys Fluent solver. Ansys Fluent is an advanced computational solver based on the finite volume method for solving the Navier-Stokes flow equations. Several dozen of geometric shapes were analysed in the optimization process of the nacelle rear part. The final result was the shape of the engine nacelle with correct flow without separation and vortex structures. The article presents results of calculations and visualization of the flow pattern for analysed cases.
Źródło:
Journal of KONES; 2017, 24, 3; 339-344
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of vibration control using laboratory test rig of wind turbine tower-nacelle system with MR damper based tuned vibration absorber
Autorzy:
Martynowicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/201323.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wind turbine vibration
tower-nacelle laboratory model
tuned vibration absorber
MR damper
tower vibration control
turbina wiatrowa
wibracje
system tower-nacelle
model laboratoryjny
tłumik drgań
MR
przepustnica
kontrola drgań
Opis:
Wind turbine tower dynamic stress is related to the fatigue wear and reliability of the whole wind turbine structure. This paper deals with the problem of tower vibration control using a specially designed and built laboratory model. The considered wind turbine tower-nacelle model consists of a vertically arranged stiff rod (representing the tower), and a system of steel plates (representing nacelle and turbine assemblies) fixed at its top. The horizontally aligned tuned vibration absorber (TVA) with magnetorheological (MR) damper is located also at the top of the rod (in nacelle system). Force excitation sources applied horizontally to the tower itself and to the nacelle were both considered. The MR damper real-time control algorithms, including ground hook control and its modification, sliding mode control, linear and nonlinear (cubic and square root) damping, and adaptive solutions are compared to the open-loop case with various constant MR damper input current values and system without MR TVA (i.e., MR TVA in “locked” state). Comprehensive experimental analyses and their results are presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 2; 347-359
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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