EFFECT OF ENGINE WEIGHT, DRAG, AND FUEL CONSUMPTION ON DIRECT OPERATING COST OF A COMMERCIAL AIRPLANE

1953 ◽  
Author(s):  
J. E. Steiner
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Direct Operating Cost

Optimum Conditions for the Operation of Airline Aircraft

1953 ◽  
Vol 57 (516) ◽  
pp. 823-824
Author(s):  
J. M. Stephenson
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Practical Case ◽  
Optimum Conditions ◽  
Realistic Approach ◽  
Direct Operating Cost ◽  
Usual Concept ◽  
Airline Company

In A. H. Stratford's interesting note in the August Journal, he assumes that an airline is presented with an aircraft of given performance, and must decide what is the best range for it to fly. Surely the practical case is the exact opposite: that an operator wishes to carry passengers or freight between two given points, and must choose between perhaps three or four available types of aircraft. Moreover, it is up to the operator to tell the manufacturers which feature he wants improved (e.g. fuel consumption, take-off distance, and so on), when he is ready to order replacements.Secondly, Mr. Stratford wishes to replace the usual concept of direct operating cost per payload ton mile by that of per cent, profit, as a measure of the efficiency of operation over a certain route. While this may be a more realistic approach to the problem of a private airline company, operating over a single route, its merit is not so obvious for the large national or subsidised airlines, which are often required to fly unprofitable routes.

Engines for a Mach 2·0 Transport

1961 ◽  
Vol 65 (602) ◽  
pp. 89-91
Author(s):  
A. V. N. Reed
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Design Criteria ◽  
Supersonic Transport ◽  
Thermodynamic Cycles ◽  
Starting Point ◽  
Direct Operating Cost ◽  
Different Types ◽  
Mach Numbers

The problem of determining the type of engine which best suits a particular application is not new to the engine designer, but the supersonic transport is perhaps unique in that a number of design criteria have been introduced which cannot easily be taken account of in the usual terms of engine weight, fuel consumption or even aircraft direct operating cost.However, an examination of the effect of these standard criteria on different types of engines is a starting point in determining what engine will best match the supersonic transport requirement. A survey of a series of thermodynamic cycles both at Mach numbers in the region of 2.0 and at subsonic speeds typical of standoff or diversion suggests that two types of engine merit further study.

scholarly journals Enabling the potential of hybrid electric propulsion through lean-burn-combustion turbofans

2021 ◽  
Vol 5 ◽  
pp. 164-176
Author(s):  
Stavros Vouros ◽  
Mavroudis Kavvalos ◽  
Smruti Sahoo ◽  
Konstantinos Kyprianidis
Keyword(s):  
Electric Propulsion ◽  
Direct Injection ◽  
Operating Cost ◽  
Pollutant Emissions ◽  
Civil Aviation ◽  
Lean Burn ◽  
Lean Direct Injection ◽  
Direct Operating Cost ◽  
Hybrid Electric ◽  
The Impact

Hybrid-electric propulsion has emerged as a promising technology to mitigate the adverse environmental impact of civil aviation. Boosting conventional gas turbines with electric power improves mission performance and operability. In this work the impact of electrification on pollutant emissions and direct operating cost of geared turbofan configurations is evaluated for an 150-passenger aircraft. A baseline two-and-a-half-shaft geared turbofan, representative of year 2035 entry-into-service technology, is employed. Parallel hybridization is implemented through coupling a battery-powered electric motor to the engine low-speed shaft. A multi-disciplinary design space exploration framework is employed comprising modelling methods for multi-point engine design, aircraft sizing, performance and pollutant emissions, mission and economic analysis. A probabilistic approach is developed considering uncertainties in the evaluation of direct operating cost. Sensitivities to electrical power system technology levels, as well as fuel price and emissions taxation are quantified at different time-frames. The benefits of lean direct injection are explored along short-, medium-, and long-range missions, demonstrating 32% NO<italic><sub>x</sub></italic> savings compared to traditional rich-burn, quick-mix, lean-burn technologies in short-range operations. The impact of electrification on the enhancement of lean direct injection benefits is investigated. For hybrid-electric powerplants, the take-off-to-cruise turbine entry temperature ratio is 2.5% lower than the baseline, extending the corresponding NO<italic><sub>x</sub></italic> reductions to the level of 46% in short-range missions. This work sheds light on the environmental and economic potential and limitations of a hybrid-electric propulsion concept towards a greener and sustainable civil aviation.

Next Generation Turboprop Gearboxes

1982 ◽  
Author(s):  
W. L. McIntire ◽  
D. A. Wagner
Keyword(s):  
Operating Cost ◽  
Past Experience ◽  
Reduction Ratio ◽  
Next Generation ◽  
Propulsion Systems ◽  
Aircraft Systems ◽  
General Arrangement ◽  
Significant Interest ◽  
Direct Operating Cost ◽  
New Generation

A new generation of fuel-efficient turboprop propulsion systems is under consideration now that fuel is a significant portion of the direct operating cost of aircraft. Systems in the 5000- to 15,000-hp (3730- to 11,185-kW) range that use conventional propellers or the new propfan are being studied. Reduction gearing for this next generation of turboprops is of significant interest due to new requirements for cruise speed life, and reliability. Detroit Diesel Allison’s past experience with the T56 family of turboprop reduction gearboxes is recounted. Probable requirements of the next generation of reduction gearboxes are discussed since new requirements for gearboxes combined with past experience should determine the profile of the next generation of gearboxes. A discussion of gearbox general arrangement and its impact on airframe installation is included, along with comments on reduction ratio, gear arrangement, accessory drives, reliability goals, and probable technology needs.

Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2009 ◽  
Author(s):  
Fernando Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Juan Carlos Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Direct Operating Cost ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behaviour. Wave rotor combustion provides semi-constant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary Multidisciplinary Design Framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, acquisition cost of the engine is higher, but engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emissions requirements.

Future Aero-Engines’ Optimisation for Minimal Operating Costs

2008 ◽  
Author(s):  
Fernando Colmenares ◽  
Daniele Pascovici ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Alexander Garci´a ◽  
...  
Keyword(s):  
Public Awareness ◽  
Operating Cost ◽  
Design Tool ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
Passenger Traffic ◽  
Direct Operating Cost ◽  
Promising Solution ◽  
Aero Engines ◽  
Bypass Ratio

While aircraft environmental performance has been important since the beginnings of commercial aviation, continuously increasing passenger traffic and a rise in public awareness have made aircraft noise and emissions two of the most pressing issues hampering commercial aviation growth today. The focus of this study is to determine the feasibility of vey-high bypass ratio, geared and contra-rotating aero engines (see figures 2–4) for short range commercial aircraft in terms of economics and environment. This involves optimising the engines’ design point to minimise the direct operating cost and evaluating the economic and environmental impact. The results present a great potential benefit of the geared turbofan compared to high BPR one (baseline) to reduce DOC; however this may involve NOx penalties, that is an increase of 11.6% in comparison to the baseline. The CRTF engine seems to be, at least according to the simulations, a very promising solution in terms of environmental and economical performance. This is one on the series of work that would be carried out using the design tool proposed. Further work on the assessment of more radical turbofans at different economical and environmental scenarios would be published when completed.

Forest Harvesting Equipment Ownership and Operating Costs in 1984

1986 ◽  
Vol 10 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Dennis A. Werblow ◽  
Frederick W. Cubbage
Keyword(s):  
Fuel Consumption ◽  
Operating Cost ◽  
Forest Harvesting ◽  
Cost Data ◽  
Operating Costs ◽  
Fixed Costs ◽  
Historical Records ◽  
The South ◽  
Consumption Data ◽  
Harvesting Systems

Abstract Forest harvesting equipment purchase costs in 1984 were determined by a survey of equipment dealers and manufacturers operating in the South. Based on delivered purchase prices, fixed costs for equipment ownership were calculated using machine rate formulas. Equipment operating costs were estimated based on general guidelines, fuel consumption data, and historical records. The fixed and operating cost data can be used when considering equipment investments and analyzing actual or potential harvesting systems.

scholarly journals Cruise Flight Performance Optimization for Minimizing Green Direct Operating Cost

2019 ◽  
Vol 11 (14) ◽  
pp. 3899 ◽  
Author(s):  
Tian ◽  
Wan ◽  
Ye ◽  
Xing
Keyword(s):  
Environmental Effects ◽  
Performance Optimization ◽  
Meteorological Data ◽  
Operating Cost ◽  
Numerical Test ◽  
Flight Performance ◽  
Time Dynamic ◽  
Direct Operating Cost ◽  
Greenhouse Effects ◽  
Cruise Flight

To cope with the environmental impact of aviation and pollution problems in the future, airlines need to assess environmental impacts and offer countermeasures in advance. In order to measure the influence of environment on the airlines’ operational costs, this paper establishes an aircraft green direct operating cost (GDOC) model to quantify adverse environmental effects, such as air pollution and greenhouse effects, into the direct operating cost (DOC). Furthermore, fuel consumption, flight time, and distance in the cruising stage account for about 80% of the entire flight mission, and optimizing cruise flight performance can contribute greatly to reduce GDOC. Therefore, this paper sets up an optimal control model to minimize GDOC, establishes a discrete time dynamic system for optimizing the cruise altitude and speed profiles, and searches the optimal results by using dynamic programming. Besides, as meteorological conditions affect aircraft aerodynamics, fuel flow rate, contrail formation, and so on, this paper analyzes meteorological uncertainty by using historic meteorological data. Finally, a route is selected as an example, and the rationality of the optimal results is proven by comparing GDOC with DOC. The results and discussion of the numerical test also show that environmental effects on aircraft operation can be reduced significantly by adopting GDOC as the optimization objective, especially the contrail cost, and the step-climb cruise mode can further reduce GDOC effectively.

scholarly journals A Firefly Algorithm Optimization-Based Equivalent Consumption Minimization Strategy for Fuel Cell Hybrid Light Rail Vehicle

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2665 ◽  
Author(s):  
Han Zhang ◽  
Jibin Yang ◽  
Jiye Zhang ◽  
Pengyun Song ◽  
Xiaohui Xu
Keyword(s):  
Fuel Cell ◽  
Fuel Consumption ◽  
Firefly Algorithm ◽  
Operating Cost ◽  
Operating Mode ◽  
Light Rail ◽  
Power Sources ◽  
Rail Vehicle ◽  
Mode Control ◽  
Equivalent Consumption Minimization Strategy

To coordinate multiple power sources properly, this paper presents an optimal control strategy for a fuel cell/battery/supercapacitor light rail vehicle. The proposed strategy, which uses the firefly algorithm to optimize the equivalent consumption minimization strategy, improves the drawback that the conventional equivalent consumption minimization strategy takes insufficient account of the global performance for the vehicle. Moreover, the strategy considers the difference between the two sets of optimized variables. The optimization objective is to minimize the daily operating cost of the vehicle, which includes the total fuel consumption, initial investment, and cycling costs of power sources. The selected case study is a 100% low-floor light rail vehicle. The advantages of the proposed strategy are investigated by comparison with the operating mode control, firefly algorithm-based operating mode control, and equivalent consumption minimization strategy. In contrast to other methods, the proposed strategy shows cost reductions of up to 39.62% (from operating mode control), 18.28% (from firefly algorithm-based operating mode control), and 13.81% (from equivalent consumption minimization strategy). In addition, the proposed strategy can reduce fuel consumption and increase the efficiency of the fuel cell system.

scholarly journals The PT6 Engine: 30 Years of Gas Turbine Technology Evolution

1993 ◽  
Author(s):  
M. Badger ◽  
A. Julien ◽  
A. D. LeBlanc ◽  
S. H. Moustapha ◽  
A. Prabhu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Low Cost ◽  
New Technology ◽  
Operating Cost ◽  
Weight Ratio ◽  
High Standard ◽  
Direct Operating Cost ◽  
Cost Development ◽  
Engine Reliability ◽  
Cycle Temperature

The PT6 engine entered service in the mid-1960’s. Since then, application of new technology, has enabled low cost development of engines approaching 1500 KW, the introduction of electronic controls, improved power-to-weight ratio, higher cycle temperature and reduced specific fuel consumption. At the same time, PT6 field experience in business, commuter, helicopter and trainer applications has resulted in engines with low Direct Operating Cost and a reputation for rugged design and a high standard of engine reliability. This paper will highlight some interesting examples of this technical evolution, including the development of electronic controls and the application of the latest 3D aerodynamic and stress analysis to both compressor and turbine components.

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