Global ETD Search

11	Characteristics of the Specific Fuel Consumption for Jet Engines Bensel, Artur January 2018 (has links) (PDF) Purpose of this project is a) the evaluation of the Thrust Specific Fuel Consumption (TSFC) of jet engines in cruise as a function of flight altitude, speed and thrust and b) the determination of the optimum cruise speed for maximum range of jet airplanes based on TSFC characteristics from a). Related to a) a literature review shows different models for the influence of altitude and speed on TSFC. A simple model describing the influence of thrust on TSFC seems not to exist in the literature. Here, openly available data was collected and evaluated. TSFC versus thrust is described by the so-called bucket curve with lowest TSFC at the bucket point at a certain thrust setting. A new simple equation was devised approximating the influence of thrust on TSFC. It was found that the influence of thrust as well as of altitude on TSFC is small and can be neglected in cruise conditions in many cases. However, TSFC is roughly a linear function of speed. This follows already from first principles. Related to b) it was found that the academically taught optimum flight speed (1.316 times minimum drag speed) for maximum range of jet airplanes is inaccurate, because the derivation is based on the unrealistic assumption of TSFC being constant with speed. Taking account of the influence of speed on TSFC and on drag, the optimum flight speed is only about 1.05 to 1.11 the minimum drag speed depending on aircraft weight. The amount of actual engine data was extremely limited in this project and the results will, therefore, only be as accurate as the input data. Results may only have a limited universal validity, because only four jet engine types were analyzed. One of the project's original value is the new simple polynomial function to estimate variations in TSFC from variations in thrust while maintaining constant speed and altitude. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Flugmechanik Flugtriebwerk Aeronautics Airplanes Airplanes--Performance Airplanes--Turbojet engines engine turbofan fuel consumption SFC TSFC PSFC Turbomatch bucket curve off-takes cruise altitude speed Mach thrust BPR data extraction optimization range Breguet
12	Aircraft Fuel Consumption - Estimation and Visualization Burzlaff, Marcus January 2017 (has links) (PDF) In order to uncover the best kept secret in today's commercial aviation, this project deals with the calculation of fuel consumption of aircraft. With only the reference of the aircraft manufacturer's information, given within the airport planning documents, a method is established that allows computing values for the fuel consumption of every aircraft in question. The aircraft's fuel consumption per passenger and 100 flown kilometers decreases rapidly with range, until a near constant level is reached around the aircraft's average range. At longer range, where payload reduction becomes necessary, fuel consumption increases significantly. Numerical results are visualized, explained, and discussed. With regard to today's increasing number of long-haul flights, the results are investigated in terms of efficiency and viability. The environmental impact of burning fuel is not considered in this report. The presented method allows calculating aircraft type specific fuel consumption based on publicly available information. In this way, the fuel consumption of every aircraft can be investigated and can be discussed openly. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Flugmechanik Flugtriebwerk Aeronautics Airplanes Airplanes--Performance Airplanes--Fuel consumption aviation commercial aircraft passenger flight mechanics flight mechanics Breguet equation fuel consumption fuel consumption fuel burn payload range airport planning document long-haul environment saving
13	Conditions for Passenger Aircraft Minimum Fuel Consumption, Direct Operating Costs and Environmental Impact Caers, Brecht January 2019 (has links) (PDF) Purpose - Find optimal flight and design parameters for three objectives: minimum fuel consumption, Direct Operating Costs (DOC), and environmental impact of a passenger jet aircraft. --- Approach - Combining multiple models (this includes aerodynamics, specific fuel consumption, DOC, and equivalent CO2 mass) into one generic model. In this combined model, each objective's importance is determined by a weighting factor. Additionally, the possibility of further optimizing this model by altering an aircraft's wing loading is analyzed. --- Research limitations - Most models use estimating equations based on first principles and statistical data. --- Practical implications - The optimal cruise altitude and speed for a specific objective can be approximated for any passenger jet aircraft. --- Social implications - By using a simple approach, the discussion of optimizing aircraft opens up to a level where everyone can participate. --- Value - To find a general answer on how to optimize aviation, operational and design-wise, by using a simple approach. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Flugzeugaerodynamik Flugmechanik Betriebskosten Aeronautics Airplanes--Performance Cost accounting Environmental protection Flugzeug Flugtriebwerk Luftverschmutzung Energieverbrauch Tabellenkalkulation Airplanes Aerodynamics Speed Altitudes Energy conservation Air--Pollution Global warming Electronic spreadsheets aviation commercial aircraft DOC Direct Operating Costs flight mechanics flight mechanics fuel consumption fuel consumption fuel burn
14	Überprüfung einer einfachen Kopfrechenmethode zur Umrechnung der Fluggeschwindigkeit von CAS in TAS Lucht, Dennis January 2019 (has links) (PDF) Zweck - Von Piloten werden u.a. die sogenannten "Manual Flying Skills" gefordert. Dabei muss der Pilot in der Lage sein (ohne Autopiloten) nach grundlegenden Instrumenten zu fliegen. Dafür sind neben Geschick auch Faustformeln erforderlich. Die Faustformeln müssen dafür verlässlich sein. Der Inhalt dieser Arbeit beschäftigt sich exemplarisch mit einer Faustformel zur Umrechnung der kalibrierten Fluggeschwindigkeit (Calibrated Airspeed, CAS) in die wahre Fluggeschwindigkeit (True Airspeed, TAS). --- Methodik - In Excel und Matlab werden die Ergebnisse aus den Berechnungen der Faustformel mit dem Ergebnis einer exakten Berechnungsweise anhand flugmechanischer Formeln verglichen. Dabei wird die Flughöhe und Fluggeschwindigkeit variiert. Es werden die Abweichungen ermittelt und in Diagrammen zwei- und dreidimensional visualisiert. --- Ergebnisse - Die zu prüfende Faustformel liefert in dem für Sie vorgesehen Anwendungsbereich hinreichend genaue Ergebnisse mit Abweichungen unter 5 %. Dabei nehmen die Abweichung zu, umso weiter die Parameter (Höhe und Geschwindigkeit) von typischen Reiseflugbedingungen entfernt sind. --- Bedeutung in der Praxis - Piloten können bedenkenlos auf die in dieser Arbeit geprüfte Faustformel zurückgreifen und kommen so mit überschaubarem Kopfrechenaufwand auf relativ genaue Ergebnisse. --- Wert - Diese Arbeit zeigt, wie mit mäßigem Zeitaufwand in Excel eine Faustformel über einen gesamten Bereich geprüft werden kann. Das Vorgehen kann auf weitere Faustformeln übertragen werden, sodass sich ein Pilot sein "Kniebrett" mit verifizierten Faustformeln füllen kann. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Flugmechanik Fluggeschwindigkeit Aeronautics Airplanes Airplanes--Performance Airspeed airplanes Flughöhe Fluggeschwindigkeit Fluginstrumente Flugzeugführer Atmosphäre Näherungsrechnung Tabellenkalkulation Wahre Fluggeschwindigkeit Kalibrierte Fluggeschwindigkeit Kopfrechnung Kniebrett Altitudes Air speed Air-speed indicators Air pilots Atmosphere Mental arithmetic Electronic spreadsheets Calibrated Airspeed CAS True Airspeed TAS Manual Flying Skills MATLAB Excel
15	Basic Comparison of Three Aircraft Concepts: Classic Jet Propulsion, Turbo-Electric Propulsion and Turbo-Hydraulic Propulsion Rodrigo, Clinton January 2019 (has links) (PDF) 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. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Flugmechanik Betriebskosten Aeronautics Airplanes Airplanes--Performance Cost accounting Ölhydraulik Flugtriebwerk Elektroantrieb Kraftstoffverbrauch Flugzeug Entwurf Dimensionierung Aeroplanes Design Airplanes--Jet propulsion Airplanes--Turbofan engines Electric propulsion Hydraulics Airplanes--Fuel consumption Environmental protection Airbus A320 aircraft aircraft design flight mechanics engines hybrid propulsion hydraulics certification DOC Direct Operating Costs Airbus A320
16	Evaluation of the Hybrid-Electric Aircraft Project Airbus E-Fan X Benegas Jayme, Diego January 2019 (has links) (PDF) 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. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Elektroantrieb Flugmechanik Aeronautics Airplanes Electric propulsion Airplanes--Performance Betriebskosten Kraftstoffverbrauch Luftverschmutzung Fluglärm Projektbewertung Technikbewertung Luftfahrttechnik Flugtriebwerk Passagier Flugzeug Entwurf Dimensionierung Cost accounting Airplanes--Fuel consumption Environmental protection Airplanes--Noise Evaluation Technology assessment Aerospace engineering Airplanes--Jet propulsion Airplanes--Turbofan engines Design aircraft aircraft design flight mechanics engines certification DOC Direct Operating Costs Airbus E-Fan X BAe 146

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