Dissertations / Theses on the topic 'Aircraft engine performance'
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1
Miao, Zhisong. "Aircraft engine performance and integration in a flying wing aircraft conceptual design." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7249.
Full textAbstract:
The increasing demand of more economical and environmentally friendly aero
engines leads to the proposal of a new concept – geared turbofan. In this thesis,
the characteristics of this kind of engine and relevant considerations of
integration on a flying wing aircraft were studied.
The studies can be divided into four levels: GTF-11 engine modelling and
performance simulation; aircraft performance calculation; nacelle design and
aerodynamic performance evaluation; preliminary engine installation.
Firstly, a geared concept engine model was constructed using TURBOMATCH
software. Based on parametric analysis and SFC target, the main cycle
parameters were selected. Then, the maximum take-off thrust was verified and
corrected from 195.56kN to 212kN to meet the requirements of take-off field
length and second segment climb. Besides, the engine performance at offdesign
points was simulated for aircraft performance calculation.
Secondly, an aircraft performance model was developed and the performance
of FW-11 was calculated on the basis of GTF-11 simulation results. Then, the
effect of GTF-11 characteristics performance on aircraft performance was
evaluated. A comparison between GTF-11 and conventional turbofan, RB211-
524B4, indicated that the aircraft can achieve a 13.1% improvement in fuel
efficiency by using the new concept engine.
Thirdly, a nacelle was designed for GTF-11 based on NACA 1-series and
empirical methods while the nacelle dimensions of conventional turbofan
RB211-525B4 were obtained by measure approach. Then, the installation thrust
losses caused by nacelle drags of the two engines were evaluated using ESDU
81024a. The results showed that the nacelle drags account for about 4.08%
and 3.09% of net thrust for GTF-11 and RB211-525B4, respectively.
Finally, the considerations of engine installation on a flying wing aircraft were
discussed and a preliminary disposition of GTF-11 on FW-11 was presented.
2
Navaratne, Rukshan. "Investigation of impact of engine degradation on optimum aircraft trajectories." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/12296.
Full textAbstract:
The continuous growth in flight operations has led to public concern regarding the impact of aviation on the environment with its anthropogenic contribution to global warming. Several solutions have been proposed in order to reduce the environmental impact of aviation. However most of them are long term solutions such as new environmental friendly aircraft and engine designs. In this respect, management of aircraft trajectory and mission is a potential short term solution that can readily be implemented. Therefore, in order to truly understand the optimised environment friendly trajectories that can be actually deployed by airlines, it is important to investigate the impact of degraded engine performance on real aircraft trajectories at multi-disciplinary level. Several trajectory optimisation studies have been conducted in this direction in the recent past, but engines considered for the studies were clean and trajectories were ideal and simple. This research aims to provide a methodology to enhance the conventional approach of the aircraft trajectory optimisation problem by including engine degradation and real aircraft flight paths within the optimisation loop (framework); thereby the impact of engine degradation on optimum aircraft trajectories were assessed by quantifying the difference in fuel burn and emissions, when flying a trajectory which has been specifically optimised for an aircraft with degraded engines and flying a trajectory which has been optimised for clean engines. For the purpose of this study models of a clean and two levels of degraded engines have been developed that are similar to engines used in short range and long range aircraft currently in service. Degradation levels have been assumed based on the deterioration levels of Exhaust Gas Temperature (EGT) margin. Aircraft performance models have been developed for short range and long range aircraft with the capability of simulating (generating) vertical and horizontal flight profiles provides by the airlines. An emission prediction model was developed to assess NOx emissions of the mission. The contrail prediction model was adopted from previous studies to predict contrail formation. In addition, a multidisciplinary aircraft trajectory optimisation framework was developed and employed to analyse short range flight trajectories between London and Amsterdam and long range flight trajectories between London and Colombo under three cases. Case_1: Aircraft with clean engines, Case_2 and Case_3 were Aircraft with two different levels of degraded engines having a 5% and 10% Exhaust Gas Temperature (EGT) increase respectively. Three different multi objective optimisation studies were performed; (1) Fuel burn vs Flight time, (2) Fuel burn vs NOx emission, and (3) Fuel burn vs Contrails. Finally optimised trajectories generated with degraded engines were compared with the optimised trajectories generated with clean engines ... [cont].
3
Yarlagadda, Santosh. "Performance Analysis of J85 Turbojet Engine Matching Thrust with Reduced Inlet Pressure to the Compressor." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1271367584.
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4
Tow, Kevin Robert. "Aircraft engine performance improvements using multistage compressors with actively controlled stall lines." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36437.
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5
Toufexis, Dimitrios. "Aircraft maintenance and development of a performance-based creep life estimation for aero engine." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7750.
Full textAbstract:
For any machine designed to generate power, or to fulfill its functions in general, maintenance actions will have an impact on many aspects of its overall capabilities, especially its performance and the length of its useful life. Since these are vital in order to generate maximum profit, the maintenance actions that affect them must be given serious consideration. For this reason, this research aims to propose a method that will enhance the cost saving potential with more accurately determined maintenance intervals and greater exploitation of the remaining life of the components by utilizing the capabilities of condition based monitoring.
Initially, the research focuses on the description and the understanding of maintenance methods as they are performed within the aviation industry, but it also aims to investigate the state of the art Condition Based Monitoring Maintenance (CBMM) and its associated advantaged relating to the older methods. The thesis begins by describing the fundamental aviation maintenance management domains, paying particular attention to CBMM, and continues with the diagnostic and prognostic methods that are in use in order to support the condition monitoring concept. Next, a description is given of the actual implementations of the CBMM process, with the presentation of the maintenance enhancement systems, namely the Central Maintenance System and the Aircraft Condition Monitoring System.
Lastly, a case study is presented of the estimation of the remaining useful life of a turbine blade, as it relates to the primary failure mode of creep. The case study endorses the use of the condition monitoring diagnostic methods discussed previously and also aims to demonstrate the predictive capabilities of the Engine Usage Diagnostics at both the design and the into-service stage. The created/simulated engine performance models concern several operating conditions of the engine while the impact of each of those on the remaining useful life of the blade is investigated.
The benefit of this research is that it proposes a practical, effective, and relatively easy way to perform maintenance by predicting the need according to the usage. Additionally, the data required have already been measured, which paves the way for the creation of more intelligent engine control units. The contribution and innovation of the research is demonstrated by the fact that no similar approaches to creep life prediction have been published for the same type of engine, namely the CFM56 5B2. Last but not least, the results are presented in the most beneficial form of remaining hours before the failure.
6
Gu, Weiqun. "Evaluation of optimised flight trajectories for conventional and novel aircraft and engine integrated systems." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/10254.
Full textAbstract:
Today, the air transport industry has become an essential element of global society by
its great contributions to the wide exchanges of cultures/people and to the rapid growth
in the world economy.
However, on the other hand, the adverse impacts on the environment caused by air
transport, such as air pollution, noise and climate change, are drawing, increasingly,
growing public concern.
In order to address the steady growth in air-travel demand in the next decades through
an environmentally-friendly way and realise the ACARE 2020 environmental goals,
The Clean Sky programme has been launched by European Union over the period 2008
– 2013.
The project research, described in this thesis and sponsored by the Clean Sky
programme, aims at evaluating the feasibility of reducing the environmental impact of
commercial aviation through the introduction of changes in the aircraft operational rules
and procedures, as well as the application of the new-generation propfan (open rotor)
engine, based on flight trajectory multidisciplinary optimisation and analysis of
commercial aircraft.
In order to accomplish the above research objectives, a complete methodology to
achieve and realise optimum flight trajectories has been initially proposed. Then, 12
component-level models which function as simulating different disciplines, such as
aircraft performance, engine performance, engine gaseous emission, and flight noise,
have been developed or selected/adopted. Further, nine system-level integration and
optimisation models were built. These system-level models simulate flights from
Amsterdam Schiphol airport in the Netherlands to Munich airport in Germany flown by
different types of aircraft through different flight phases with different optimisation
objectives. Finally, detailed investigations into the flight trajectory optimisations were
performed, extensive optimisation results were achieved and corresponding description,
analysis and comparisons were provided.
The main contributions of this work to knowledge broadly comprise the following: 1)
the further development regarding the methodology of flight trajectory multidisciplinary
optimisation; 2) previous work on aircraft trajectory optimisation has often considered
fixed objectives over the complete flight trajectory. This research focused on
representative flight phases of a flight mission with different optimisation objectives,
namely, noise impact and fuel burn during the departure phase; fuel burn and flight time
during en route phase; and noise impact and NOx emission during the arrival phase; 3)
this research has extended the current flight trajectory optimisations to turboprop and
propfan equipped aircraft. As a result, a relative complete 2D flight trajectory
multidisciplinary optimisation spectrum, spanned by primary commercial aircraft types,
primary flight phases and primary optimisation objectives of interest, has been built.
Although encouraging progress have been achieved, this project research, as with any
other research activity, is also only ‘on the way’ rather than coming to the ‘end’ point.
There are still many aspects which can be improved further and there is still much new
research and exploration which can be investigated further. All these have also been
suggested in this thesis.
7
Materano, Blanco Gilberto Ignacio. "Numerical modelling of pressure rise combustion for reducing emissions of future civil aircraft." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9259.
Full textAbstract:
This work assesses the feasibility of designing and implementing the wave rotor
(WR), the pulse detonation engine (PDE) and the internal combustion wave
rotor (ICWR) as part of novel Brayton cycles able to reduce emissions of future
aircraft. The design and evaluation processes are performed using the
simplified analytical solution of the devices as well as 1D-CFD models. A code
based on the finite volume method is built to predict the position and
dimensions of the slots for the WR and ICWR. The mass and momentum
equations are coupled through a modified SIMPLE algorithm to model
compressible flow. The code includes a novel tracking technique to ensure the
global mass balance. A code based on the method of characteristics is built to
predict the profiles of temperature, pressure and velocity at the discharge of the
PDE and the effect of the PDEs array when it operates as combustion chamber
of gas turbines. The detonation is modelled by using the NASA-CEA code as a
subroutine whilst the method of characteristics incorporates a model to capture
the throttling and non-throttling conditions obtained at the PDE's open end
during the transient process. A medium-sized engine for business jets is
selected to perform the evaluation that includes parameters such as specific
thrust, specific fuel consumption and efficiency of energy conversion. The ICWR
offers the best performance followed by the PDE; both options operate with a
low specific fuel consumption and higher specific thrust. The detonation in an
ICWR does not require an external source of energy, but the PDE array
designed is simple. The WR produced an increase in the turbine performance,
but not as high as the other two devices. These results enable the statement
that a pressure rise combustion process behaves better than pressure
exchangers for this size of gas turbine. Further attention must be given to the
NOx emission, since the detonation process is able to cause temperatures
above 2000 K while dilution air could be an important source of oxygen.
8
Woods, Nathan Michael. "Taking Off in Africa: Critical Elements of Aircraft Engine Manufacturer Engagement That Can Affect Airline Safety Performance." Antioch University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1578644754400526.
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9
Kline, Sara E. "An Investigation of the Performance of Compliant Finger Seals for use in Gas Turbine Engines using Navier-Stokes and Reynolds Equation Based Numerical Models and Experimental Evaluation." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1478984223281402.
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10
Hrabovský, Matúš. "Posouzení letových vlastností a zatížení malého sportovního letounu po modifikaci pohonné jednotky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417471.
Full textAbstract:
The thesis deals with the issue of replacement of the Rotax 912 ULS engine with the Rotax 915 iSc3 B engine and its impact on flight performance, characteristics and airframe loads of the WT 9 Dynamic. For accomplish better maneuverability tail surfaces are enlarged. Both versions of airplane with different engines and tails surfaces are quantified with respect to airframe loads and flight characteristics. The output of the diploma thesis can be used for strength design of airplane structure and stress tests of the new modification of the WT 9 Dynamic aircraft.
11
Outirba, Bilal. "Experimental study of the performance and endurance of carbon fiber brush seals for aero-engines bearing chambers." Doctoral thesis, Universite Libre de Bruxelles, 2017. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/258495.
Full textAbstract:
Over the last decades, it has been progressively acknowledged that reducing the specific fuel consumption and the emission of pollutants as well as improving the thrust-to-weight ratio involves extensive research on advanced sealing technologies. Amongst these, brush seals are particularly well considered for their excellent leakage performance, their low friction properties, and their ability to cope with inevitable rotor excursions during flights. This thesis presents the experimental work that has been carried on in order to characterize carbon brush seals performance in function of the bristle pack geometry and the operating conditions. The analyzed parameters are the bristle free length, the density, and the inter-platedistance. The work, performed by the ULB in collaboration with French engine manufacturer Safran Aircraft Engines, provides first, a description of the test installation that reproduces accurately the severe working conditions encountered in a bearing chamber. A total of eight samples were submitted to extensive testing, and allowed to perform a qualitative analysis of the main performance indicators of a brush seal: the leakage flow, and the seal torque. Complex phenomena acting on the bristle pack were put in evidence under the effect of differential pressure androtation speed, and oil, which fundamentally deteriorate the leakage performance of a brush seal. Subsequently, performance models were developed through empirical correlations, based on the experimental data. They predict the leakage flow and the seal torque as a function of the geometrical parameters and operating conditions. In addition, hysteresis issues were also addressed, and an IR camera helped investigating the heat generation properties of a brush seal.Brush seal samples were submitted to endurance testing, in order to highlight wear mechanisms, and study the performance degradation with the operating time. Oil plays a major part in extending brush seals operating life, despite the leakage performance degradation. Finally, the correlations developed throughout the PhD thesis were used to develop an optimization process in function of the operating conditions of a modern aero-engine. Ultimately, large savings in air consumption were put in evidence when replacing labyrinth seals by brush seals.Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished
12
Glassock, Richard R. "Design, modelling and measurement of hybrid powerplant for unmanned aerial vehicles (UAVs)." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/61052/1/Richard_Glassock_Thesis.pdf.
Full textAbstract:
The success or effectiveness for any aircraft design is a function of many trade-offs.
Over the last 100 years of aircraft design these trade-offs have been optimized and dominant aircraft design philosophies have emerged. Pilotless aircraft (or uninhabited airborne systems, UAS) present new challenges in the optimization of their configuration.
Recent developments in battery and motor technology have seen an upsurge in the utility and performance of electric powered aircraft. Thus, the opportunity to explore hybrid-electric aircraft powerplant configurations is compelling. This thesis considers the design of such a configuration from an overall propulsive, and energy efficiency perspective. A prototype system was constructed using a representative small UAS internal combustion engine (10cc methanol two-stroke) and a 600W brushless Direct current (BLDC) motor. These components were chosen to be representative of those that would be found on typical small UAS.
The system was tested on a dynamometer in a wind-tunnel and the results show an improvement in overall propulsive efficiency of 17% when compared to a non-hybrid powerplant. In this case, the improvement results from the utilization of a larger propeller that the hybrid solution allows, which shows that general efficiency improvements are possible using hybrid configurations for aircraft propulsion.
Additionally this approach provides new improvements in operational and mission flexibility (such as the provision of self-starting) which are outlined in the thesis.
Specifically, the opportunity to use the windmilling propeller for energy regeneration was explored. It was found (in the prototype configuration) that significant power (60W) is recoverable in a steep dive, and although the efficiency of regeneration is low, the capability can allow several options for improved mission viability.
The thesis concludes with the general statement that a hybrid powerplant improves the overall mission effectiveness and propulsive efficiency of small UAS.
13
Gongol, Jakub. "Návrh malého proudového motoru do 1kN tahu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230963.
Full textAbstract:
This work will be focused on issue of a jet engine. The thesis will be divided into search retrieval part and computational part. In the search retrieval part it will focus on different configurations of jet engines as well as areas of their use. The main part of the thesis will however focus on a calculations where a turbine, compressor and an exhaust nozzle will be designed in order to give a thrust of approximately 1kN. Next step will be determination of an engine charcteristic that will give us a preview on how the engine performance will look like in off-design modes.
14
Mutschall, Marcel. "Die Genauigkeit einer vereinfachten Berechnung der Steigzeit von Flugzeugen." Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2018. http://d-nb.info/1175497711.
Full textAbstract:
Ziel - Die Zeit die ein Flugzeug benötigt, um auf eine bestimmte Höhe zu steigen (die
Steigzeit) kann mit einer Formel berechnet werden, die vereinfachend annimmt, dass die
Steiggeschwindigkeit über dem gesamten Steigflug mit zunehmender Höhe linear abnimmt.
Ziel der Untersuchung ist, zu ermitteln, ob die Annahme einer linear abnehmenden
Steiggeschwindigkeit realistisch ist bzw. welche Fehler sich aus der Annahme ergeben.
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Methode - Mit der Höhe ändern sich Parameter wie Luftdichte, Widerstand, Schub und damit
auch die optimale Fluggeschwindigkeit für den Steigflug. Die Parameter beeinflussen sich
dabei gegenseitig. Der Schub wird dabei nach drei unterschiedlichen Methoden berechnet,
gegeben von Bräunling, Scholz und Howe. Analysiert wird der Verlauf des Schubes mit der
Höhe und der Verlauf der Steiggeschwindigkeit mit der Höhe für jede der drei
Schubberechnungen. Abschließend wird für jede Schubberechnung die Steigzeit verglichen
wie sie sich ergibt a) aus der einfachen Formel und b) aus einer Integrationsberechnung, bei
der der Verlauf der Steiggeschwindigkeit durch eine Funktion beschrieben wird.
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Ergebnisse - Die drei Schubberechnungen liefern ausgehend vom gleichen Startschub
unterschiedliche Schübe in der Höhe. In die Methode nach Bräunling gehen mehr Parameter
ein als in die anderen beiden Methoden. Es kann angenommen werden, dass die Methode
nach Bräunling genauer ist, der Beweis kann aber nicht geführt werden. Der Schub nach
Scholz und Howe fällt nahezu linear mit der Höhe ab. Der Schubverlauf nach Bräunling zeigt
eine deutliche Nichtlinearität. Es wird die Steigzeit von 0 km auf 11 km Höhe berechnet nach
a) und b), mit jeder der drei Schubberechnungen. Dabei wird jeweils der Unterschied in der
Steigzeit ermittelt. Aufgrund der Nichtlinearität im Schubverlauf zeigt die Methode nach
Bräunling dann auch den größten Unterschied zwischen den Berechnungsmethoden von
7,1 %. Bei einer Schubberechnung nach Scholz ergeben sich 1,7 % und nach Howe 1,4 %.
Wenn bereits zu Beginn Vereinfachungen, z.B. bezüglich des Triebwerksschubes,
vorgenommen wurden, ist es in Hinblick auf den Aufwand und die zu erreicheneden
Ergebnisse möglich, und zum Teil sinnvoll, die Berechnungen der Steigzeit mittels linearer
Abnahme der vertikalen Geschwindigkeit durchzuführen. Es wird ausdrücklich darauf
hingewiesen, dass es hier um den Vergleich von zwei Methoden zur Berechnung der Steigzeit
geht und nicht um die Bewertung von Methoden zur Schubberechnung (für die keine
Vergleichswerte vorlagen).
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Praktischer Nutzen - Es konnte festgestellt werden, dass eine einfache Formel zur
Berechnung der Steigzeit mit geringem Fehler angewandt werden kann - insbesondere wenn
Methoden zur Schubberechnung vorliegen, bei denen der Schub annähernd linear mit der
Höhe abnimmt. Bei großem Aufwand und realitätsnaher Betrachtung, z.B. nach Bräunling,
führt der lineare Ansatz jedoch zu einem zu großen Fehler. Hierfür sollte die Berechnung der
Steigzeit mittels Integration durchgeführt werden.
15
Horák, Marek. "Návrh dvoumotorového letounu kategorie pro sběrnou dopravu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228595.
Full textAbstract:
This master’s thesis deal with design of EV-55 Outback airplane with pressurized cabin. In this thesis are given common principles and requirements of regulations on construction pressurized cabin. A necessary fuselage modifications and fuselage construction are included. Also construction and build up of air-conditioning system and emergency oxygen system are included. Some parts of this thesis are about weight and balance, definition of pressurized cabin load, simple stability analysis and basic flight performance calculation. At the end of this master’s thesis a result of weight and flight performances are compared with analogous airplanes by other producers.
16
Seďa, Ondřej. "Modifikace letounu RAPID 200 pro vlekání." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228984.
Full textAbstract:
This master’s thesis deal with design modification of the RAPID 200 (Skyleader 200) airplane for towing at compliance with maximum take-off weight 450 kilogramme. A necessary construction modification, a weight analysis these adjustments and a balance verification are included. The thesis contains of power plants installation consisting from the M 132 engine and the V 541.2 propeller, a towing gear and a landing gear, a load calculation of power plants and towing gear and basic flight performance calculation too. Last but not least valuation of operation ekonomy, operation characteristics assesment and a using of the airplane for specialized duty are included.
17
Naeem, Muhamma. "Implications of aero-engine deterioration for a military aircraft's performance." Thesis, Cranfield University, 1999. http://hdl.handle.net/1826/3397.
Full textAbstract:
World developments have led the armed forces of many countries to become more
aware of how their increasingly stringent financial budgets are spent. Major expenditure
for military authorities is upon aero-engines. Some in-service deterioration in any
mechanical device, such as an aircraft's gas-turbine engine, is inevitable. However, its
extent and rate depend upon the qualities of design and manufacture, as well as on the
maintenance/repair practices followed by the users. Each deterioration has an adverse
effect on the performance and shortens the reliable operational life of the engine thereby
resulting in higher life cycle costs. The adverse effect on the life-cycle cost can be reduced
by determining the realistic fuel and life-usage and by having a better knowledge of the
effects of each such deterioration on operational performance. Subsequently improvements
can be made in the design and manufacture of adversely-affected components as well as
with respect to maintenance / repair and operating practices.
For a military aircraft's mission-profiles (consisting of several flight-segments),
using computer simulations, the consequences of engine deterioration upon the aircraft's
operational-effectiveness as well as fuel and life usage are predicted. These will help in
making wiser management decisions (such as whether to remove the aero-engines from the
aircraft for maintenance or to continue using them with some changes in the aircraft's
mission profile), with the various types and extents of engine deterioration. Hence
improved engine utilization, lower overall life-cycle costs and the optimal mission
operational effectiveness for a squadron of aircraft can be achieved.
18
Puller, Tomáš. "Remotorizace letounu EV-55 Outback." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229461.
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Thesis Remotorization of the aircraft EV-55 Outback deals with possibility of installationt piston diesel engine instead of turboprop engine PT6A-21. Begining of this thesis deals with choice of convenient engine and propeller. Then, 3D model of engine bed is designed, followed by mass analysis. Based on results from the mass analysis and requirements from the CS - 23 regulation, load is specified and stress analysis is done. The other part of this thesis deals with adjustment of the airframe and with calculation of flight performances. Finally, economic indices are specified.
19
Benegas, Jayme Diego. "Evaluation of the Hybrid-Electric Aircraft Project Airbus E-Fan X." Master's thesis, Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2019. http://d-nb.info/1204685894.
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Purpose - This master thesis evaluates the hybrid-electric aircraft project E-Fan X with respect to its economical and environmental performance in comparison to its reference aircraft, the BAe 146-100. The E-Fan X is replacing one of the four jet engines of the reference aircraft by an electric motor and a fan. A turboshaft engine in the cargo compartment drives a generator to power the electric motor. --- Methodology - The evaluation of this project is based on standard aircraft design equations. Economics are based on Direct Operating Costs (DOC), which are calculated with the method of the Association of European Airlines (AEA) from 1989, inflated to 2019 values. Environmental impact is assessed based on local air quality (NOx, Ozone and Particulate Matter), climate impact (CO2, NOx, Aircraft-Induced Cloudiness known as AIC) and noise pollution estimated with fundamental acoustic equations. --- Findings - The battery on board the E-Fan X it is not necessary. In order to improve the proposed design, the battery was eliminated. Nevertheless, due to additional parts required in the new configuration, the aircraft is 902 kg heavier. The turboshaft engine saves only 59 kg of fuel. The additional mass has to be compensated by a payload reduced by 9 passengers. The DOC per seat-mile are up by more than 10% and equivalent CO2 per seat-mile are more than 16% up in the new aircraft. --- Research limitations - Results are limited in accuracy by the underlying standard aircraft design calculations. The results are also limited in accuracy by the lack of knowledge of some data of the project. --- Practical implications - The report contributes arguments to the discussion about electric flight. --- Social implications - Results show that unconditional praise given to the environmental characteristics of this industry project are not justified.
20
Rodrigo, Clinton. "Basic Comparison of Three Aircraft Concepts: Classic Jet Propulsion, Turbo-Electric Propulsion and Turbo-Hydraulic Propulsion." Master's thesis, Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2019. http://d-nb.info/1204558019.
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Purpose - This thesis presents a comparison of aircraft design concepts to identify the superior propulsion system model among turbo-hydraulic, turbo-electric and classic jet propulsion with respect to Direct Operating Costs (DOC), environmental impact and fuel burn. --- Approach - A simple aircraft model was designed based on the Top-Level Aircraft Requirements of the Airbus A320 passenger aircraft, and novel engine concepts were integrated to establish new models. Numerous types of propulsion system configurations were created by varying the type of gas turbine engine and number of propulsors. --- Findings - After an elaborate comparison of the aforementioned concepts, the all turbo-hydraulic propulsion system is found to be superior to the all turbo-electric propulsion system. A new propulsion system concept was developed by combining the thrust of a turbofan engine and utilizing the power produced by the turbo-hydraulic propulsion system that is delivered via propellers. The new partial turbo-hydraulic propulsion concept in which 20% of the total cruise power is coming from the (hydraulic driven) propellers is even more efficient than an all turbo-hydraulic concept in terms of DOC, environmental impact and fuel burn. --- Research Limitations - The aircraft were modelled with a spreadsheet based on handbook methods and relevant statistics. The investigation was done only for one type of reference aircraft and one route. A detailed analysis with a greater number of reference aircraft and types of routes could lead to other results. --- Practical Implications - With the provided spreadsheet, the DOC and environmental impact can be approximated for any commercial reference aircraft combined with the aforementioned propulsion system concepts. --- Social Implications - Based on the results of this thesis, the public will be able to discuss the demerits of otherwise highly lauded electric propulsion concepts. --- Value - To evaluate the viability of the hydraulic propulsion systems for passenger aircraft using simple mass models and aircraft design concept.
21
Bereczky, Horst Zoltan. "Alternative power unit for light, commercial aircraft: design and performance modeling." Thesis, 2008. http://hdl.handle.net/10539/4589.
Full textAbstract:
ABSTRACT
Developments in the field of microturbine technology and gas turbine driven
aircraft has been progressing without much progress in light aircraft
predominantly propelled by piston engines. Because of inhibitive maintenance
and overhaul costs of such however, propulsion via a gas turbine engine has
been proposed with the potential of eventually replacing current engine
configurations. Subsequently, the objective was to conceptually design a
replacement gas turbine engine in the 150 kW range.
A selection of case studies was used to illustrate the changing technologies to
illustrate the technological viability of micro-gas turbines for light aircraft.
Advantages and disadvantages of both engine types were discussed and a
concise description of gas turbine operations and its components was given.
A brief overview of fundamentals as well as the transmission layout was also
supplied. Three configurations were isolated, namely the single spool design, a
twin spool design featuring a free power turbine and the effect of a fuel
conserving recuperator.
Calculations were performed using Microsoft Excel, which proved sufficient in
effectively calculating complex formulae - even under the necessary iterative
feed-back conditions the design process demanded.
Eventually, variable-specific design criteria were derived regarding the three
engine types. Because fuel consumption still proved inhibitive, the effect of
recuperation was investigated which yielded a very competitive engine - should
the possibility of recuperator technology exist on time.
As a result, one particular recuperated, single spool gas turbine engine was
successfully identified. Having met all the design criteria sufficiently, this
preliminary prototype design was numerically described and put within context
of principal, peripheral working components such as a compatible gearbox
layout.
22
Chi, Wu Ying, and 吳英麒. "A Study of the Relationships among Technology, Transfer Modes and Transfer Modes Performance of ROCAF Aircraft Engine Overhaul Center." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/41459495263626930680.
Full textAbstract:
碩士樹德科技大學
經營管理研究所
95
For the modernized combat requirement,weapon system and associated equipments’ performance and reliability are two key issues that into account. In order to maintain the readiness of these equipments, improving maintenance technology level of armed forces equipments is much more important than before. At present,most of the maintenance technology in the field of armed forces equipments is still imported by the foreign countries. The maintenance technology transfer is getting more critical especially to the phases during maintenance capability establishment. According to the literature review,the studies related to the maintenance technology transfer are very limited.Most of these survey reports studies are mainly regarding the GOCO(government own company operate),without taking complexity or further assessment. This research takes one engine depot of ROCAF as an example, to investigate the influences and differences among maintenance technology, transfer mode, as well as it’s performance. This research conducted the questionnaire investigation, and applied the statistic analysis method. The retrieved valid questionnaires are calculated up to 291 of 362 copies, and the effective returned rate is 85.08%. The conclusions of this research show that during the engine maintenance capability establishment, there will have different technology transfer performance by different maintenance transfer modes. And selection of technology modes will be affected by different maintenance capability, motivation of technology receiving, and characteristics of maintenance technology. The maintenance technology of employees will also affect the technology transfer mode performance. In the phase of performance awareness, most of the employees supposed the way of technology manual study by themselves is better than the other two. Maybe the way of study by themselves is considered saving more time. The selection of technology transfer will be affected by maintenance technology characteristics and capability. The more complicated the technology is, the higher motivation of technology requirement. The better technology capability is, the higher awareness of performance. The results of this research can be a reference for Armed Forces to establish engine maintenance capability in the future.
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NENG, LEE SHUNG, and 李順能. "The Relationships among Change Perceptions, Work Attitudes and Work Performance of the Employees under Organizational Change — A Case of Military Aircraft Engine Maintenance Shop." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/34903141668377179378.
Full textAbstract:
碩士樹德科技大學
經營管理研究所
93
With the globalization and the increased competitions among businesses in recent years, the implementation of organizational changes in various enterprises has already become the trend. "Jingjin Program"(The ROC Armed Forces Streamlining Program) was one of the decisive conducts for the Department of Defense. The purpose of the present study was to investigate the relationships among change perceptions, work attitudes, and work performance of employees in Military Aircraft Engine Maintenance Shop after implementation of Jingjin Program. Four hundred and fifteen questionnaires were distributed with a valid return rate of 69%. The findings indicated that overall, the employees had very low recognitions toward Jingjin Program. Among them, the employees with the age ranged from 20 to 29 had stronger perceptions toward “communication policies” than their counterparts since the contents of Jingjin Program have greater impacts on their future work and lives. Moreover, sergeants reported to have better work attitudes and work performance since they had greater concerns on their future career development and finance to be considered. It is also found that change perceptions did significantly affected employees’ work attitudes and work performance. Therefore, the researcher suggested that leaders, when implementing organizational changes, should acknowledge that effective communicating change policies with the employees is the key to success. By way of effective communications between organization and the employees, the change purposes could be understood and implemented. Through proper counseling, employees’ negative psychological issues could be resolved. Thus, it will lead to desirable outcomes of organizational changes.
24
Chien-ChinSu and 蘇芊菫. "Study on Strategic Promotion for Performance-Based Logistics to Aircraft Engines." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/60872736222334663530.
Full text
25
Tseng, Chih Yu, and 曾梓昱. "Aviation Fuel Efficiency Enhancement Based on Model Analysis of Aircraft and Engine Performances." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/73000764394613469493.
Full textAbstract:
碩士中華科技大學
飛機系統工程研究所
101
The aviation fuel consumption has always been the key factor for the airline's operating cost. Since the amount of worldwide fuel usage for the transport aircraft is huge and the fuel cost is up surging, how to reduce the fuel consumption and the carbon emission is an urgent problem in aviation industrial circles. The objective for the present study is to show that the application of a model-based method based on flight data and FCOM (Flight Crew Operating Manuals) can provide strategies as how to enhance fuel efficiency for commercial transports. The fuel efficiency, engine health, and aircraft performance are closely related. The standard models of exhaust gas temperature (EGT) and lift-to-drag ratio (L/D) can be established by using fuzzy-logic modeling (FLM) techniques. And then, the excessive fuel consumption and optimum cruising altitude can be estimated numerically through the analysis of model-based derivatives. The excessive fuel consumption due to the effects of deficiencies will be estimated in the present study. According to the model-predicted results, if the causes on deficiency per influencing flight variable can be solved, the total potential fuel saving will be 19.2%.
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"The Supersonic Performance of High Bypass Ratio Turbofan Engines with Fixed Conical Spike Inlets." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.49114.
Full textAbstract:
abstract: The objective of this study is to understand how to integrate conical spike external compression inlets with high bypass turbofan engines for application on future supersonic airliners. Many performance problems arise when inlets are matched with engines as inlets come with a plethora of limitations and losses that greatly affect an engine’s ability to operate. These limitations and losses include drag due to inlet spillage, bleed ducts, and bypass doors, as well as the maximum and minimum values of mass flow ratio at each Mach number that define when an engine can no longer function. A collection of tools was developed that allow one to calculate the raw propulsion data of an engine, match the propulsion data with an inlet, calculate the aerodynamic data of an aircraft, and combine the propulsion and aerodynamic data to calculate the installed performance of the entire propulsion system. Several trade studies were performed that tested how changing specific design parameters of the engine affected propulsion performance. These engine trade studies proved that high bypass turbofan engines could be developed with external compression inlets and retain effective supersonic performance. Several engines of efficient fuel consumption and differing bypass ratios were developed through the engine trade studies and used with the aerodynamic data of the Concorde to test the aircraft performance of a supersonic airliner using these engines. It was found that none of the engines that were tested came close to matching the supersonic performance that the Concorde could achieve with its own turbojet engines. It is possible to speculate from the results several different reasons why these turbofan engines were unable to function effectively with the Concorde. These speculations show that more tests and trade studies need to be performed in order to determine if high bypass turbofan engines can be developed for effective usage with supersonic airliners in any possible way.Dissertation/Thesis
Run file and text files from the propulsion simulations performed in NPSS.
Input and output file used in EDET to generate aerodynamic data of Concorde.
Five column propulsion data of tested engines after inlet matching.
Masters Thesis Aerospace Engineering 2018
27
Cheng, Wen-Ming, and 鄭溫鳴. "A Study on the Relationship between Transfer Modes and Their Performances for the Weapon Equipment’s Maintenance Technology — Case of an Aircraft Engine Accessory Overhaul Center in ROCAF." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/87919197710672953077.
Full textAbstract:
碩士國防管理學院
資源管理研究所
89
Most of the researches on the models of technology transfer are focus on the relationships between the overall performance and their affecting factors of technology transfer as well as their individual performances and their affecting factors under specific technology transfer models such as FDI, Joint Venture, and Licensing. This research is to divide the mode of the weapon equipment’s maintenance technology transfer into the explicit and tacit modes of technology transfer under the licensing models. In addition, this research will discuss relationships between the individual performance of technology transfer modes and their affecting factors moer deeply for acquiring a set of model of more optimal selections of technology transfer modes on the weapon equipment’s maintenance technology transfer. Herein the methodology is to build up a study structure by means of the paper study and 3-practical-case study, then achieve a questionnaire to all maintenance technology personnel in an aircraft engine accessory overhaul center in ROCAF to prove. The result shows that the different modes of maintenance technology transfer will cause different performances of technology transfer, and also the acquisition channels, technology characteristics, the technology capability of maintenance personnel, and the motive of technology acquisition will influence selections of technology transfer modes actually.