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.

Future Aero-Engines’ Optimisation for Minimal Fuel Burn

2008 ◽  
Author(s):  
Fernando Colmenares ◽  
Konstantinos Kyprianidis ◽  
Josue´ Go´mez ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
...  
Keyword(s):  
Public Awareness ◽  
Commercial Aviation ◽  
Passenger Traffic ◽  
Fuel Burn ◽  
Technical Issues ◽  
Promising Solution ◽  
Environmental Requirements ◽  
Aero Engines ◽  
Set Up ◽  
Year 2000

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 air transportation for the new millennium will require revolutionary solutions to meeting public demand for improving safety, reliability, environmental compatibility, and affordability. The objective of this research is to assess the trade-off between operating costs and environmental requirements of the future aero engines for short range commercial aircrafts. This involves optimising the engines’ design point to minimise the block fuel and evaluating the economic and environmental impact. A high by-pass ratio turbofan engine with performance characteristics and technology from the year 2000 was set up as a baseline and compared to very high by-pass ratio turbofans. The results present a great potential benefit of the geared turbofan compared to high BPR one (baseline) to reduce cruise CO2 emissions and noise; however this may involve NOx penalties, that is an increase of 5.1% 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 on the cycles being assessed in this paper (feasibility study). Further work on the specific technical issues — such as: technological implications — would be published when completed.

State of the Art in Aircraft Gas Turbine Technology

1985 ◽  
Author(s):  
S. R. Sampl ◽  
M. E. Shank
Keyword(s):  
State Of The Art ◽  
Operating Cost ◽  
Environmental Benefits ◽  
Advanced Technology ◽  
Turbine Engines ◽  
Commercial Aircraft ◽  
Turbofan Engines ◽  
Cost Of Ownership ◽  
Direct Operating Cost ◽  
The Cost

The new series of turbofan engines use advanced technology features which enhance their attractiveness through reductions in the cost of ownership, noise, and pollution. Improvements in aerodynamics, mechanics, electronics, and materials technology reduce the cost of ownership via such factors as cost, reliability, durability, and operability. Primarily, advanced technology addresses fuel consumption, a parameter with a very large effect on direct operating cost. In addition, these advances do not trade convenience of operation for environmental acceptability. The advanced technology concepts used in the new commercial aircraft turbine engines offer both economic and environmental benefits.

scholarly journals Parameterization of a Conventional and Regenerated UHB Turbofan

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Fábio Oliveira ◽  
Francisco Brójo
Keyword(s):  
Fuel Consumption ◽  
First Generation ◽  
Specific Fuel Consumption ◽  
Aircraft Engines ◽  
Turbofan Engine ◽  
Commercial Aviation ◽  
Technological Developments ◽  
Specific Thrust ◽  
Aero Engines ◽  
Bypass Ratio

AbstractThe attempt to improve aircraft engines efficiency resulted in the evolution from turbojets to the first generation low bypass ratio turbofans. Today, high bypass ratio turbofans are the most traditional type of engine in commercial aviation. Following many years of technological developments and improvements, this type of engine has proved to be the most reliable facing the commercial aviation requirements. In search of more efficiency, the engine manufacturers tend to increase the bypass ratio leading to ultra-high bypass ratio (UHB) engines. Increased bypass ratio has clear benefits in terms of propulsion system like reducing the specific fuel consumption. This study is aimed at a parametric analysis of a UHB turbofan engine focused on short haul flights. Two cycle configurations (conventional and regenerated) were studied, and estimated values of their specific fuel consumption (TSFC) and specific thrust (Fs) were determined. Results demonstrate that the regenerated cycle may contribute towards a more economic and friendly aero engines in a higher range of bypass ratio.

Design Study for a Fuel Efficient Turbofan Engine

1980 ◽  
Author(s):  
R. C. Kingcombe ◽  
S. W. Dunning
Keyword(s):  
Pressure Ratio ◽  
Operating Cost ◽  
Engine Performance ◽  
Design Study ◽  
Technological Advances ◽  
Engine Design ◽  
Direct Operating Cost ◽  
Specific Thrust ◽  
The One ◽  
Bypass Ratio

An engine design study is presented in which the target is a 15 percent reduction in installed specific fuel consumption over the large engines currently in service while still meeting anticipated noise and emissions regulations. The fuel saving is achieved with a low specific thrust (bypass ratio 10) and a high overall cycle pressure ratio (42 at cruise). A three-shaft design is proposed, employing highly loaded components in order to reduce the number of turbomachinery stages and hence keep down cost and weight. It is argued that this approach is the one most compatible with projected technological advances. The engine configuration is given and the key features explained, highlighting areas where further research would be of particular advantage. Finally, the predicted engine performance is given, together with an estimate of the savings in direct operating cost.

Ultra High Bypass Ratio Engine Sizing and Cycle Selection Study for a Subsonic Commercial Aircraft in the N+2 Timeframe

2011 ◽  
Author(s):  
Brian K. Kestner ◽  
Jeff S. Schutte ◽  
Jonathan C. Gladin ◽  
Dimitri N. Mavris
Keyword(s):  
Pressure Ratio ◽  
Important Variable ◽  
Direct Drive ◽  
Commercial Aircraft ◽  
Low Pressure Turbine ◽  
Fuel Burn ◽  
Technology Transition ◽  
Fundamental Research ◽  
Bypass Ratio ◽  
Engine Cycle

This paper presents an engine sizing and cycle selection study of ultra high bypass ratio engines applied to a subsonic commercial aircraft in the N+2 (2020) timeframe. NASA has created the Environmentally Responsible Aviation (ERA) project to serve as a technology transition bridge between fundamental research (TRL 1–4) and potential users (TRL 7). Specifically, ERA is focused on subsonic transport technologies that could reach TRL 6 by 2020 and are capable of integration into an advanced vehicle concept that simultaneously meets the ERA project metrics for noise, emissions, and fuel burn. An important variable in exploring the trade space is the selection of the optimal engine cycle for use on the advanced aircraft. In this paper, two specific ultra high bypass engine cycle options will be explored: advanced direct drive and geared turbofan. The advanced direct drive turbofan is an improved version of conventional turbofans. In terms of both bypass ratio and overall pressure ratio, the advanced direct turbofan benefits from improvements in aerodynamic design of its components, as well as material stress and temperature properties. By putting a gear between the fan and the low pressure turbine, a geared turbo fan allows both components to operate at optimal speeds, thus further improving overall cycle efficiency relative to a conventional turbofan. In this study, sensitivity of cycle design with level of technology will be explored, in terms of both cycle parameters (such as specific thrust consumption (TSFC) and bypass ratio) and aircraft mission parameters (such as fuel burn and noise). To demonstrate this sensitivity, engines will be sized for optimal performance on a 300 passenger class aircraft for a 2010 level technology tube and wing airframe, a N+2 level technology tube and wing air-frame, and finally on a N+2 level technology blended wing body airframe with and without boundary layer ingestion (BLI) engines.

Validation of MISES Two-Dimensional Boundary Layer Code for High-Pressure Turbine Aerodynamic Design

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Philip L. Andrew ◽  
Harika S. Kahveci
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Operating Cost ◽  
Design Tool ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
High Pressure Turbine ◽  
Reduce Operating Cost ◽  
Wide Range ◽  
Dimensional Boundary

Avoiding aerodynamic separation and excessive shock losses in gas turbine turbomachinery components can reduce fuel usage and thus reduce operating cost. In order to achieve this, blading designs should be made robust to a wide range of operating conditions. Consequently, a design tool is needed—one that can be executed quickly for each of many operating conditions and on each of several design sections, which will accurately capture loss, turning, and loading. This paper presents the validation of a boundary layer code, MISES, versus experimental data from a 2D linear cascade approximating the performance of a moderately loaded mid-pitch section from a modern aircraft high-pressure turbine. The validation versus measured loading, turning, and total pressure loss is presented for a range of exit Mach numbers from ≈0.5 to 1.2 and across a range of incidence from −10 deg to +14.5 deg relative to design incidence.

scholarly journals Breaking the Barriers

2012 ◽  
Vol 134 (05) ◽  
pp. 32-37
Author(s):  
Lee S. Langston
Keyword(s):  
Fluid Mechanics ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Solid Mechanics ◽  
Commercial Aircraft ◽  
Commercial Aviation ◽  
New Developments ◽  
Exhaust Heat ◽  
Turbine Component ◽  
Made In

This article explores the new developments in the field of gas turbines and the recent progress that has been made in the industry. The gas turbine industry has had its ups and downs over the past 20 years, but the production of engines for commercial aircraft has become the source for most of its growth of late. Pratt & Whitney’s recent introduction of its new geared turbofan engine is an example of the primacy of engine technology in aviation. Many advances in commercial aviation gas turbine technology are first developed under military contracts, since jet fighters push their engines to the limit. Distributed generation and cogeneration, where the exhaust heat is used directly, are other frontiers for gas turbines. Work in fluid mechanics, heat transfer, and solid mechanics has led to continued advances in compressor and turbine component performance and life. In addition, gas turbine combustion is constantly being improved through chemical and fluid mechanics research.

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.

Characteristics of a co-flowing jet with varying lip thickness and constant bypass ratio

2019 ◽  
Vol 91 (9) ◽  
pp. 1205-1213 ◽  
Author(s):  
Naren Shankar R. ◽  
Kevin Bennett S.
Keyword(s):  
Design Methodology ◽  
Critical Value ◽  
Commercial Aircraft ◽  
Critical Limit ◽  
Potential Core ◽  
Content Type ◽  
Free Jet ◽  
The Past ◽  
Bypass Ratio ◽  
Practical Implications

Purpose Subsonic commercial aircraft operate with turbo-fan engines that operate with moderate bypass ratio (BR) co-flowing jets (CFJ). This study aims to analyse CFJ with constant BR 6.3 and varying primary nozzle lip thickness (LT) to find a critical LT in CFJ below which mixing enhances and beyond which mixing inhibits. Design/methodology/approach CFJ were characterized with a constant BR of 6.3 and varying lip thicknesses. A single free jet with a diameter equal to that of a primary nozzle of the co-flowing jet was also studied for comparison. Findings The results show that within a critical limit, the mixing enhanced with an increase in LT. This was signified by a reduction in potential core length (PCL). Beyond this limit, mixing inhibited leading to the elongation of PCL. This limit was controlled by parameters such as LT and magnitude of BR. Practical implications The BR value of CFJ in the present study was 6.3. This lies under the moderate BR value at which subsonic commercial turbofan operates. Hence, it becomes impervious to study its mixing behavior. Originality/value This is the first effort to find the critical value of LT for a constant BR for compressible co-flow jets. The CFJ with moderate BR and varying LT has not been studied in the past. The present study focuses on finding a critical LT below which mixing enhances and above which mixing inhibits.

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.

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