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Future civil aircraft engines Anders Lundbladh. Boeing ”superefficient airplane” 7E7. Two lobe body gives more design freedom for passanger and freight space. A-A. 7/8 seats wide. “Raked wingtip” from 777-300ER and 767-400ER. Long pods for engines with mixed flow ? BPR~10 Nozzle from
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Boeing ”superefficient airplane” 7E7 Two lobe body gives more design freedom for passanger and freight space A-A 7/8 seats wide “Raked wingtip” from 777-300ER and 767-400ER Long pods for engines with mixed flow ? BPR~10 Nozzle from CF34-10 A A A A Long slender wings Composite technology form the Sonic Cruiser Tail wedge from MD-11 Volvo Aero Engines, Anders Lundbladh
Range and passanger A330 (also with new engines) shorter range than 7E7 777-200LR not built yet 7E7-domestic close to 757 & A300/310 7E7 gives ”777-range” for 200-pass. class 7E7s long range leaves a regions around present 767 New engine Volvo Aero Engines, Anders Lundbladh
Engine Technology RR TRENT 900 • Basically builds on TRENT900/GP7000/GE90 • Small improvements possible on compressor and turbine • Higher BPR ca 10, OPR 45-50 • Slowly moving fans • Much emphasis on low weight, aluminum • More Electric Aircraft • SFC approx 14.5 mg/Ns at cruise M=0.85 • Ca 8% better than CF6-80 on B767/A330 • Ca 2% better than TRENT900/GP7000/GE90-115 VAC ICC Volvo Aero Engines, Anders Lundbladh
Fuel consumption 7E7-baseline comsumes approx. 10-15% less than 767-300ER 9% less than A330-200 7E7-stretch comsumes approx. 14% less than A330-200 and 9% less than777-300ER domestic as 757 & 15-20% better than A300/310 Volvo Aero Engines, Anders Lundbladh
How efficient is an engine ? SFC = vflight /( FHV tot ) tot = core transfer propulsive thermal Volvo Aero Engines, Anders Lundbladh
Engine type and exhaust velocity Rolls-Royce Turbofan BPR 7-8 vut = 400 m/s GE UnDucted Fan BPR 25 vut=280 m/s MTU Geared Fan BPR 14 vut=340 m/s Volvo Aero Engines, Anders Lundbladh
Specific fuel consumption SFC mg/Ns Turbofan BPR 7 Shock losses from fan blades Geared Fan BPR 14 Typical Cruise Speed M=0.78-0.85 Unducted Fan BPR 25 Volvo Aero Engines, Anders Lundbladh
Measuring points Aircraft/Engine-parameters Affecting Certification Noise Data Approach: Correlates mainly with drag and thrust needed during approach Sideline: Depends mainly on the emitted sound energy from the jet. The dominant factor is the total installed thrust and to some extent the jet specific thrust (jet velocity - although the variation from engine to engine is quite small) Takeoff: Depends mainly on the speed of climb which sets the distance to the measuring station [1/d^2] and the power of the noise source (see sideline). The rate of climb is set by the excess thrust/weight Sideline 450 m off centre line Takeoff Approach 6500m from brake release 2500 m from runway start Heathrow noise classification based on mean of sideline and takeoff Night landing restrictions from 2002: 95.9 EPNdBA 2-engine aircraft has more installed thrust than 4-engine aircraft Volvo Aero Engines, Anders Lundbladh
Driving Forces in Airline Engine DesignStakeholder Needs and ”Wants” • Travelers • safety, cost of travel, speed, cabin noise and air quality • Airlines • safety, cost,fuel consumption, maintenance (cost) • Aircraft integrators • airframe compatibility, thrust, size & weight • Airport neighbors • safety, exterior noise • Authorities, public • safety, environmentally impacting emissions Volvo Aero Engines, Anders Lundbladh
Fuel Efficiency Trends & Factors • Since the fifties the fuel consumption of jetliners has been decreased by more than 50% … • … stemming from more efficient aircraft … • Better aerodynamics • More efficient packing • New lighter materials and improved construction • … & more efficient engines … • Better materials & cooled turbines allowing higher temperatures. • Optimizing for higher temps higher pressures. • Arrival and optimization of the bypass turbofan. • … but configuration changes have been few component technology has been pressed close to the limit. Volvo Aero Engines, Anders Lundbladh
New Engine ConfigurationsAdvantages • Geared fans • Potentially lower weight • Unducted fans (propfans) • Higher propulsive efficiency • Heatexchanged cycles • Higher thermal efficiency through: • recovery of unused thermal exhaust energy • decrease of compression work • Constant volume combustion • Higher thermal efficiency Volvo Aero Engines, Anders Lundbladh
Engine Cycle Selection • Aim for low operating cost • Preliminary studies may aim to minimize • engine+fuel weight • take off weight • Engine cycle must be translated into fuel burn, engine weight, installation weight and drag • Engine layout may be used to compute engine weight Volvo Aero Engines, Anders Lundbladh
The Positive Carousel Effect Lower drag Smaller,lighter, aircraft Lower thrust Less mission fuel Smaller engines Higher specific power Higher engine efficiency Volvo Aero Engines, Anders Lundbladh