Energy efficient engine
ENERGY EFFICIENT ENGINE
Flight Propulsion System - Final Design and Analysis
BY D.Y. DAVIS AND E.M. STEARNS
Prepared for National Aeronautics and Space Administration
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Energy efficient engine
The Energy Efficient Engine (E3) is a NASA program to create fuel saving technology for future transport engines. The Flight Propulsion System (FPS) is the engine designed to achieve E goals.
Achieving these goals required aerodynamic, mechanical and system technologies advanced beyond that of current production engines. These technologies have been successfully demonstrated in component rigs, a core engine and a turbofan ground test engine. The design and benefits of the FPS are presented in this report.
All goals for efficiency, environmental considerations, and economic payoff were met. The FPS has, at maximum cruise, 10.67 km (35,000 ft), MO. 8, standard day, a 16.9% lower installed specific fuel consumption than a CF6-50C. It provides an 8.6% reduction in direct operating cost for a short haul domestic transport and a 16.2% reduction for an international long distance transport.
Achieving these goals required aerodynamic, mechanical and system technologies advanced beyond that of current production engines. These technologies have been successfully demonstrated in component rigs, a core engine and a turbofan ground test engine. The design and benefits of the FPS are presented in this report.
All goals for efficiency, environmental considerations, and economic payoff were met. The FPS has, at maximum cruise, 10.67 km (35,000 ft), MO. 8, standard day, a 16.9% lower installed specific fuel consumption than a CF6-50C. It provides an 8.6% reduction in direct operating cost for a short haul domestic transport and a 16.2% reduction for an international long distance transport.
FOREWORD
This report presents the final preliminary analysis and design of an advanced Flight Propulsion System (FPS) conducted by the General Electric Company. This work was performed for the National Aeronautics and Space Administration (NASA), Lewis Research Center, under Contract NAS3-20643 as part of the Aircraft Energy Efficiency (ACEE) Program, Energy Efficient Engine Project. Mr. Carl C. Ciepluch was the NASA Project Manager; Mr. Peter G. Batterton was the NASA Assistant Project Manager. Mr. Roger Chamberlin was the NASA Project Engineer responsible for the effort associated with the Flight Propulsion System - Final Analysis and Design reported herein. Mr. Donald Y. Davis was Manager of the E Project for the General Electric Company.
TABLE OF CONTENTS
- FLIGHT PROPULSION SYSTEM DESIGN AND ANALYSIS
- CYCLE AND ENGINE PERFORMANCE
- COMPONENT AND SYSTEM DESIGN AND PERFORMANCE
- FAN
- COMPRESSOR
- COMBUSTOR
- HIGH PRESSURE TURBINE
- LOW PRESSURE TURBINE
- TURBINE FRAME
- SUMPS, DRIVES, CONFIGURATION, AND LUBE SYSTEM
- EXHAUST SYSTEM
- NACELLE
- CONTROL SYSTEM
- DYNAMIC SYSTEM
- ENGINE/AIRCRAFT INTEGRATION
SUMMARY
The Energy Efficient Engine program is part of the National Aeronautics and Space Administration (NASA) Aircraft Energy Efficiency program. The objective of this program is to substantially improve the efficiency of commercial transport aircraft which would enter service in the late 1980's and early 1990' s.
NASA established specific performance, economic, and environmental goals for the Energy Efficient Engine program. The General Electric Flight Propulsion System (FPS) meets these goals. These goals and the current status are shown in Table I. The FPS design was reported first in 1980 and updated in 1982. This report presents the final design and the economic benefits of the FPS.
The Energy Efficient Engine program FPS design is self-contained, ready to mount and interface with the aircraft pylon. It incorporates advances in technology beyond that employed for engines currently in service. To evaluate these new technologies, the Energy Efficient Engine program included rig tests of each component, a core engine test, and a turbofan engine test.
The General Electric Energy Efficient Engine FPS features include:
- A long duct, mixed-flow, acoustically treated bulk absorber nacelle incorporating a cascade-type thrust reverser.
- A core-mounted accessory drive module.
- A highly efficient, wide-chord, 32-blade fan and debris-separating booster module.
- A 10-stage, 23:1 pressure ratio compressor.
- A double annular combustor for low emissions.
- A highly efficient two-stage high pressure turbine and a five-stage low pressure turbine.
- A two-frame, five-bearing design.
- Spring-mounted bearing supports with viscous damping on the core thrust bearing.
- A full authority digital electronic control (FADEC).
- A mixer to combine fan and core exhaust flows.
- Case cooling systems to actively control blade tip clearances in the compressor, high pressure turbine, and low pressure turbine.
- Composite materials and advanced manufacturing techniques.
- Component efficiency levels above previous state of the art.
The FPS engine is shown in Figure 1.
The component test program has been completed. Component performance results are shown in Table II.
The core engine and integrated core/low spool (ICLS) engine tests have been completed. The results of ICLS testing exceeded the performance goals established in the Energy Efficient Engine program. During both core and ICLS tests, the engines operated without aerothermal or mechanical problems. At sea level static, standard day takeoff, specific fuel consumption of 0.0332 kg/hr-N (0.326 lbm/ hr-lbf) was measured during testing of the heavily instrumented ICLS turbofan engine.
The specific fuel consumption projected for the FPS is based on improvement which can conservatively be expected during the development of a production engine. Because many components achieved performance levels significantly better than their goal levels, the component performance requirements for FPS have been increased. Final component requirements are shown in Table II. Based on these component performance levels, optimized cooling flow utilization and cycle rematching, the uninstalled (no nacelle drag) specific fuel consumption at standard day maximum cruise conditions projected for the Energy Efficient Engine program.
Energy Efficient Engine program direct operating cost is now 8.6% to 16.2% lower than a typical current production engine, the CF6-50. This range covers a spectrum of aircraft size and flight lengths.
The objective of the Energy Efficient Engine program is the development of technology to improve the energy efficiency of propulsion systems for subsonic commercial aircraft introduced in the late 1980's.
The following technical goals were established by NASA for the fully developed Energy Efficient Engine program Flight Propulsion System:
- Fuel Consumption - Minimum of 12% reduction in installed sfc compared to a CF6-50C at maximum cruise thrust, Mach 0.8 at 10.67 km (35,000 ft) altitude on a standard day with no bleed or power extraction.
- Direct Operating Cost - Minimum of 5% reduction from CF6-50C on equivalent aircraft.
- Noise - Comply with FAR 36 (1978).
- Emissions - Comply with EPA Proposed 1981 Standards for new engines.
- Performance Retention - Minimum of 50% reduction in the rate of performance deterioration in service as compared to the CF6-50C.
The NASA/General Electric Energy Efficient Flight Propulsion System achieves high propulsive efficiency by utilizing a low fan pressure ratio and a mixer than combines the fan and core streams prior to discharging them through a common exhaust nozzle. Higher thermal efficiency is achieved by using higher engine pressure ratio, increased high pressure turbine inlet temperatures, and improved component performance compared to engines such as the CF6-50C.
DOWNLOAD FREE BOOK: Energy efficient engine
NASA established specific performance, economic, and environmental goals for the Energy Efficient Engine program. The General Electric Flight Propulsion System (FPS) meets these goals. These goals and the current status are shown in Table I. The FPS design was reported first in 1980 and updated in 1982. This report presents the final design and the economic benefits of the FPS.
The Energy Efficient Engine program FPS design is self-contained, ready to mount and interface with the aircraft pylon. It incorporates advances in technology beyond that employed for engines currently in service. To evaluate these new technologies, the Energy Efficient Engine program included rig tests of each component, a core engine test, and a turbofan engine test.
The General Electric Energy Efficient Engine FPS features include:
- A long duct, mixed-flow, acoustically treated bulk absorber nacelle incorporating a cascade-type thrust reverser.
- A core-mounted accessory drive module.
- A highly efficient, wide-chord, 32-blade fan and debris-separating booster module.
- A 10-stage, 23:1 pressure ratio compressor.
- A double annular combustor for low emissions.
- A highly efficient two-stage high pressure turbine and a five-stage low pressure turbine.
- A two-frame, five-bearing design.
- Spring-mounted bearing supports with viscous damping on the core thrust bearing.
- A full authority digital electronic control (FADEC).
- A mixer to combine fan and core exhaust flows.
- Case cooling systems to actively control blade tip clearances in the compressor, high pressure turbine, and low pressure turbine.
- Composite materials and advanced manufacturing techniques.
- Component efficiency levels above previous state of the art.
The FPS engine is shown in Figure 1.
The component test program has been completed. Component performance results are shown in Table II.
The core engine and integrated core/low spool (ICLS) engine tests have been completed. The results of ICLS testing exceeded the performance goals established in the Energy Efficient Engine program. During both core and ICLS tests, the engines operated without aerothermal or mechanical problems. At sea level static, standard day takeoff, specific fuel consumption of 0.0332 kg/hr-N (0.326 lbm/ hr-lbf) was measured during testing of the heavily instrumented ICLS turbofan engine.
The specific fuel consumption projected for the FPS is based on improvement which can conservatively be expected during the development of a production engine. Because many components achieved performance levels significantly better than their goal levels, the component performance requirements for FPS have been increased. Final component requirements are shown in Table II. Based on these component performance levels, optimized cooling flow utilization and cycle rematching, the uninstalled (no nacelle drag) specific fuel consumption at standard day maximum cruise conditions projected for the Energy Efficient Engine program.
Energy Efficient Engine program direct operating cost is now 8.6% to 16.2% lower than a typical current production engine, the CF6-50. This range covers a spectrum of aircraft size and flight lengths.
The objective of the Energy Efficient Engine program is the development of technology to improve the energy efficiency of propulsion systems for subsonic commercial aircraft introduced in the late 1980's.
The following technical goals were established by NASA for the fully developed Energy Efficient Engine program Flight Propulsion System:
- Fuel Consumption - Minimum of 12% reduction in installed sfc compared to a CF6-50C at maximum cruise thrust, Mach 0.8 at 10.67 km (35,000 ft) altitude on a standard day with no bleed or power extraction.
- Direct Operating Cost - Minimum of 5% reduction from CF6-50C on equivalent aircraft.
- Noise - Comply with FAR 36 (1978).
- Emissions - Comply with EPA Proposed 1981 Standards for new engines.
- Performance Retention - Minimum of 50% reduction in the rate of performance deterioration in service as compared to the CF6-50C.
The NASA/General Electric Energy Efficient Flight Propulsion System achieves high propulsive efficiency by utilizing a low fan pressure ratio and a mixer than combines the fan and core streams prior to discharging them through a common exhaust nozzle. Higher thermal efficiency is achieved by using higher engine pressure ratio, increased high pressure turbine inlet temperatures, and improved component performance compared to engines such as the CF6-50C.
DOWNLOAD FREE BOOK: Energy efficient engine
