scholarly journals Modelling Geared Turbofan and Open Rotor Engine Performance for Year-2050 Long-Range and Short-Range Aircraft

2019 ◽  
Author(s):  
Joshua Sebastiampillai ◽  
Florian Jacob ◽  
Francesco S. Mastropierro ◽  
Andrew Rolt
Keyword(s):  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Fuel Burn ◽  
Trade Offs ◽  
Medium Range ◽  
Open Rotor ◽  
And Performance ◽  
Year 2000 ◽  
Bypass Ratio

Abstract The paper provides design and performance data for two envisaged year-2050 state-of-the-art engines: a geared high bypass turbofan for intercontinental missions and a contra-rotating pusher open rotor targeting short to medium range aircraft. It defines component performance and cycle parameters, general powerplant arrangements, sizes and weights. Reduced thrust requirements for future aircraft reflect expected improvements in engine and airframe technologies. Advanced simulation platforms have been developed, using the software PROOSIS, to model the engines and details of individual components, including custom elements for the open rotor engine. The engines are optimised and compared with ‘baseline’ year-2000 turbofans and an anticipated year-2025 entry-into-service open rotor to quantify the relative fuel-burn benefits. A preliminary scaling with non-optimised year-2050 ‘reference’ engines, based on Top-of-Climb (TOC) thrust and bypass ratio, highlights the trade-offs between reduced specific fuel consumption (SFC) and increased weight and engine diameter. These parameters are then converted into mission fuel burn using linear and non-linear trade factors from aircraft models. The final turbofan has an optimised design-point bypass ratio (BPR) of 16.8, and a maximum overall pressure ratio (OPR) of 75.4 for a 31.5% TOC thrust reduction and a 46% mission fuel burn reduction per passenger kilometre compared to the respective year-2000 baseline engine and aircraft combination. The final open rotor SFC is 9.5% less than the year-2025 open rotor and 39% less than the year-2000 turbofan, while the TOC thrust increases by 8% versus the 2025 open rotor, due to assumed increase in aircraft passenger capacity. Combined with airframe improvements, the final open rotor-powered aircraft has a 59% fuel-burn reduction per passenger kilometre relative to its year-2000 baseline.

scholarly journals Modeling Geared Turbofan and Open Rotor Engine Performance for Year-2050 Long-Range and Short-Range Aircraft

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Francesco S. Mastropierro ◽  
Joshua Sebastiampillai ◽  
Florian Jacob ◽  
Andrew Rolt
Keyword(s):  
Short Range ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Optimized Design ◽  
Fuel Burn ◽  
Medium Range ◽  
Open Rotor ◽  
And Performance ◽  
Year 2000 ◽  
Bypass Ratio

Abstract This paper provides design and performance data for two envisaged year-2050 engines: a geared high bypass turbofan for intercontinental missions and a contra-rotating pusher open rotor targeting short to medium range aircraft. It defines component performance and cycle parameters, general arrangements, sizes, and weights. Reduced thrust requirements reflect expected improvements in engine and airframe technologies. Advanced simulation platforms have been developed to model the engines and details of individual components. The engines are optimized and compared with “baseline” year-2000 turbofans and an anticipated year-2025 open rotor to quantify the relative fuel-burn benefits. A preliminary scaling with year-2050 “reference” engines, highlights tradeoffs between reduced specific fuel consumption (SFC) and increased engine weight and diameter. These parameters are converted into mission fuel burn variations using linear and nonlinear trade factors (NLTF). The final turbofan has an optimized design-point bypass ratio (BPR) of 16.8, and a maximum overall pressure ratio (OPR) of 75.4, for a 31.5% TOC thrust reduction and a 46% mission fuel burn reduction per passenger kilometer compared to the respective “baseline” engine–aircraft combination. The open rotor SFC is 9.5% less than the year-2025 open rotor and 39% less than the year-2000 turbofan, while the TOC thrust increases by 8% versus the 2025 open rotor, due to assumed increase in passenger capacity. Combined with airframe improvements, the final open rotor-powered aircraft has a 59% fuel-burn reduction per passenger kilometer relative to its baseline.

scholarly journals Design Approach for an Optimum Prop-Fan Propulsion System

1985 ◽  
Author(s):  
Gerald L. Brines
Keyword(s):  
Short Range ◽  
Propulsion System ◽  
Operating Costs ◽  
Fuel Savings ◽  
Fuel Burn ◽  
Trade Offs ◽  
Counter Rotation ◽  
Medium Range ◽  
And Performance ◽  
Design Options

The predicted potential performance of the Prop-Fan offers a major improvement in the energy efficiency of future, short-range to medium-range transports. This paper describes the approach taken in designing an optimum Prop-Fan propulsion system. Trade-offs in the configuration(s) and performance are discussed, as are the important aspects of integrating the propeller, gearbox, engine, inlet, exhaust, and nacelle. Realizing the impressive potential fuel savings of the Prop-Fan will require very careful engine/airframe integration. Design options that will be compared are: a single-rotation versus counter-rotation arrangement, a tractor versus pusher installation, and wing versus fuselage mounting. In summary, the performance of turbofan powered and Prop-Fan powered, short-haul transports will be compared in detail by using fuel burn, operating costs, and noise as criteria.

scholarly journals Ideal Power Output — An Alternative Aircraft Engine Performance Comparator

1997 ◽  
Author(s):  
Marvin F. Schmidt ◽  
Christopher M. Norden ◽  
Jeffrey M. Stricker
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
The State ◽  
Power Cycle ◽  
Shaft Power ◽  
Bypass Ratio

The gas turbine is applied in four basic configurations; the turbojet, the turbofan, the turboprop and the turboshaft. Comparisons of the performance of these various configurations is difficult since they convert the energy to different forms, i.e. thrust or shaft power. Cycle variables which do not necessarily constitute advancements in the state-of-the-art such as bypass ratio and fan pressure ratio can have a profound effect on thrust and shaft power. Differences in flight speed and altitude capability further confound the comparisons. What is required is a comparison methodology that removes all of these variables and yet puts all the various types of engines on an equitable basis. This paper will provide such a comparison tool. All turbomachinery, regardless of configuration, can be compared with this method.

Conceptual Design and Mission Analysis for a Geared Turbofan and an Open Rotor Configuration

2011 ◽  
Author(s):  
Linda Larsson ◽  
Tomas Gro¨nstedt ◽  
Konstantinos G. Kyprianidis
Keyword(s):  
Engine Performance ◽  
Aircraft Design ◽  
Service Level ◽  
Engine Emissions ◽  
Multidisciplinary Study ◽  
Multidisciplinary Analysis ◽  
Open Rotor ◽  
Specific Thrust ◽  
And Performance ◽  
Bypass Ratio

In this multidisciplinary study a geared open rotor configuration is assessed and compared to an ultra high bypass ratio geared turbofan engine. Both designs assume a 2020 entry into service level of technology. The specific thrust level for minimizing block fuel and the resulting engine emissions for a given mission is sought. The tool used contains models that effectively capture: engine performance, mechanical and aerodynamic design, engine weight, emissions, aircraft design and performance as well as direct operating costs. The choice of specific thrust is a complex optimization problem and several disciplines need to be considered simultaneously. It will be demonstrated, through multidisciplinary analysis, that the open rotor concept can offer a substantial fuel saving potential, compared to ducted fans, for a given set of design considerations and customer requirements.

Open Rotor Engine Cycle Modeling and Performance Assessment

2020 ◽  
Author(s):  
Ziyu Zhang ◽  
Li Zhou ◽  
Xiaobo Zhang ◽  
Zhanxue Wang
Keyword(s):  
Engine Performance ◽  
Performance Model ◽  
Civil Aviation ◽  
Environment Impact ◽  
Turbine Performance ◽  
New Concepts ◽  
Open Rotor ◽  
Potential Impact ◽  
And Performance ◽  
Bypass Ratio

Abstract Aiming to enable dramatic reductions in the environment impact and fuel consumption of future civil aviation, NASA and European related research institutions are committed to developing new concepts and technologies in which counter rotating open rotor (CROR) concept can achieve this objective. In order to evaluate its potential impact, an open rotor engine performance model needs to be established. This paper presents the modeling method of an open rotor engine with the geared counter rotating open rotor (GOR) as object, and implements it in an in-house modular program of gas turbine performance prediction. In addition, the steady-state performance of the model is analyzed, and the model accuracy is verified based on the existing data. On this basis, the performance of open rotor engine and high bypass ratio turbofan engine is compared and results show that the counter rotating open rotor engine has obvious fuel saving advantages.

scholarly journals CFD Study of Nozzle Configurations for Ultra High Bypass Engines

1993 ◽  
Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Thrust Coefficient ◽  
Optimum Range ◽  
Installation Effects ◽  
Wide Range ◽  
And Performance ◽  
Aircraft Aerodynamics ◽  
Bypass Ratio

Performance and aerodynamic aspects of ultra-high bypass ratio ducted engines have been investigated with an emphasis on nozzle aerodynamics. The interference with aircraft aerodynamics could not be covered. Numerical methods were used for aerodynamic investigations of geometrically different aft end configurations for bypass ratios between 12 and 18, this is the optimum range for long missions which will be important for future civil engine applications. Results are presented for a wide range of operating conditions and effects on engine performance are discussed. The limitations for higher bypass ratios than 12 to 18 do not come from nozzle aerodynamics but from installation effects. It is shown that using CFD and performance calculations an improved aerodynamic design can be achieved. Based on existing correlations, for thrust and mass-flow, or using aerodynamic tailoring by CFD and including performance investigations, it is possible to increase the thrust coefficient up to 1%.

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.

Performance Study for the Benefits of a Variable Pitch Composite Fan

2010 ◽  
Author(s):  
Robert S. Mazzawy
Keyword(s):  
New Technology ◽  
Fuel Efficiency ◽  
Performance Study ◽  
Full Spectrum ◽  
Variable Pitch ◽  
Fuel Burn ◽  
Power Setting ◽  
Fan Blade ◽  
And Performance ◽  
Bypass Ratio

This paper describes the installed performance potential for a recently patented new design concept for a variable pitch composite fan blade [1,2]. The unique characteristic of this design is the compactness and light weight of the assembly of fan plus variable pitch mechanism. This design enables turbofan engine cycles with higher propulsive efficiency that previously were not viable due to high installation weight and performance penalties. As part of its mandate to support new technology that improves fuel efficiency, the Connecticut Coalition for the Advancement of Technology (CCAT) sponsored a study to quantify the potential savings. A comparison is made between a current high bypass ratio engine and an advanced very high bypass ratio engine both configured to deliver approximately 30,000 lbs of thrust at the sea level static takeoff (SLTO) power setting. These engines are evaluated to determine the installed thrust and fuel consumption characteristics over the full spectrum of flight operation, enabling fuel burn to be evaluated for any aircraft mission. For a nominal mission profile considered in this paper, the advanced engine cycle enabled by the use of the variable pitch composite fan blade provided more than 12% reduction in fuel burn.

Effects of Advanced Engine Technology on Open Rotor Cycle Selection and Performance

2012 ◽  
Author(s):  
Christopher A. Perullo ◽  
Jimmy C. M. Tai ◽  
Dimitri N. Mavris
Keyword(s):  
Fuel Efficiency ◽  
Sharp Decrease ◽  
Holistic Approach ◽  
Carbon Dioxide Production ◽  
Fuel Prices ◽  
Fuel Burn ◽  
Open Rotor ◽  
Institute Of Technology ◽  
Bypass Ratio ◽  
Rotor Model

Recent increases in fuel prices and increased focus on aviation’s environmental impacts have reignited focus on the open rotor engine concept. This type of architecture was extensively investigated in previous decades but was not pursued through to commercialization due to relatively high noise levels and a sudden, sharp decrease in fuel prices. More recent increases in fuel prices and increased government pressure from taxing carbon-dioxide production mean the open rotor is once again being investigated as a viable concept. Advances in aero-acoustic design tools have allowed industry and academia to re-investigate the open rotor with an increased emphasis on noise reduction while retaining the fuel burn benefits due to the increased propulsive efficiency. Recent research with conceptual level multidisciplinary considerations of the open rotor has been performed [1], but there remains a need for a holistic approach that includes the coupled effects of the engine and airframe on fuel burn, emissions, and noise. Years of research at Georgia Institute of Technology have led to the development of the Environmental Design Space (EDS) [2]. EDS serves to capture interdependencies at the conceptual design level of fuel burn, emissions, and noise for conventional and advanced engine and airframe architectures. Recently, leveraging NASA Environmentally Responsible Aviation (ERA) modeling efforts, EDS has been updated to include an open rotor model to capture, in an integrated fashion, the effects of an open rotor on conventional airframe designs. Due to the object oriented nature of EDS, the focus has been on designing modular elements that can be updated as research progresses. A power management scheme has also been developed with the future capability to trade between fuel efficiency and noise using the variable pitch propeller system. Since the original GE open rotor test was performed using a military core, there is interest in seeing the effect of modern core-engine technology on the integrated open rotor performance. This research applies the modular EDS open rotor model in an engine cycle study to investigate the sensitivity of thermal efficiency improvements on open rotor performance, including the effects on weight and vehicle performance. The results are that advances in the core cycle are necessary to enable future bypass ratio growth and the trades between core operating temperatures and size become more significant as bypass ratio continues to increase. A general benefit of a 30% reduction in block fuel is seen on a 737–800 sized aircraft.

Effects of Advanced Engine Technology on Open Rotor Cycle Selection and Performance

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Christopher A. Perullo ◽  
Jimmy C. M. Tai ◽  
Dimitri N. Mavris
Keyword(s):  
Design Space ◽  
Environmental Design ◽  
Sharp Decrease ◽  
Multidisciplinary Optimization ◽  
Fuel Prices ◽  
Fuel Burn ◽  
Open Rotor ◽  
Institute Of Technology ◽  
Bypass Ratio ◽  
Rotor Model

Recent increases in fuel prices and increased focus on aviation's environmental impacts have reignited focus on the open rotor engine concept. This type of architecture was extensively investigated in previous decades but was not pursued through to commercialization due to relatively high noise levels and a sudden, sharp decrease in fuel prices. More recent increases in fuel prices and increased government pressure from taxing carbon-dioxide production mean the open rotor is once again being investigated as a viable concept. Advances in aero-acoustic design tools have allowed industry and academia to re-investigate the open rotor with an increased emphasis on noise reduction while retaining the fuel burn benefits due to the increased propulsive efficiency. Recent research with conceptual level multidisciplinary considerations of the open rotor has been performed (Bellocq et al., 2010, “Advanced Open Rotor Performance Modeling For Multidisciplinary Optimization Assessments,” Paper No. GT2010-2963), but there remains a need for a holistic approach that includes the coupled effects of the engine and airframe on fuel burn, emissions, and noise. Years of research at Georgia Institute of Technology have led to the development of the Environmental Design Space (EDS) (Kirby and Mavris, 2008, “The Environmental Design Space,” Proceedings of the 26th International Congress of the Aeronautical Sciences). EDS serves to capture interdependencies at the conceptual design level of fuel burn, emissions, and noise for conventional and advanced engine and airframe architectures. Recently, leveraging NASA environmentally responsible aviation (ERA) modeling efforts, EDS has been updated to include an open rotor model to capture, in an integrated fashion, the effects of an open rotor on conventional airframe designs. Due to the object oriented nature of EDS, the focus has been on designing modular elements that can be updated as research progresses. A power management scheme has also been developed with the future capability to trade between fuel efficiency and noise using the variable pitch propeller system. Since the original GE open rotor test was performed using a military core, there is interest in seeing the effect of modern core-engine technology on the integrated open rotor performance. This research applies the modular EDS open rotor model in an engine cycle study to investigate the sensitivity of thermal efficiency improvements on open rotor performance, including the effects on weight and vehicle performance. The results are that advances in the core cycle are necessary to enable future bypass ratio growth and the trades between core operating temperatures and size become more significant as bypass ratio continues to increase. A general benefit of a 30% reduction in block fuel is seen on a 737-800 sized aircraft.

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