Document
Visions of the Future:
Hybrid Electric Aircraft Propulsion
Cheryl Bowman AIAA Aircraft Electric/Hybrid - Electric Power & Propulsion Workshop, July 28, 2016 National Aeronautics and Space Administration
Outline
• NASA’s Motivation for Electrified Aircraft Propulsion
Investment
• Strategic Thrust 4: Transition to Low Carbon Propulsion
• Hybrid and Electric Aircraft Propulsion Terminology
• NASA’s Approach to Electrified Aircraft Propulsion
• Convergent Aeronautics Solutions: for High Risk and High
Payoff
• SCEPTOR/X - 57: Near Term Flight Demonstration
• Advanced Air Transport Technology: Long Term Aircraft
Investment for Electrified Propulsion
• Summary
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Electrified Aircraft Propulsion : Motivation
NASA Aeronautics Research Mission Directorate
Mega Drivers
Strategic Thrusts
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Electrified Aircraft Propulsion : Motivation
Strategic Thrusts Guide Investment Targets
2015 2025 2035 Introduction of Low - Carbon Fuels for Conventional Initial Introduction of Introduction of Alternative Engines and Exploration of Alternative Propulsion Propulsion Systems to Alternative Propulsion Systems Aircraft of All Sizes Systems
The Low Carbon Challenge is to enable carbon - neutral growth in
aircraft operations: www.nasa.gov National Aeronautics and Space Administration
Electrified Aircraft Propulsion Terminology
• Electrified Propulsion refers to the use of electric
power for aircraft propulsion
– Could be all or partially electric propulsion – Other aircraft development programs use the terms “More electric” or “All electric” as the use of electric power for secondary systems on aircraft such as control surfaces and wing de - icing
• Hybrid Electric has two meanings in aircraft context
– One meaning is the use of two power sources, such as turbine engine and electric motor, to drive the fan (or propeller) on an aircraft — hybrid electric powertrain – Another meaning is the combination of more than one propulsive sources such as engines , turboelectric energy generation, fuel cells energy generation, or battery energy storage — hybrid electric prolusion
• Turboelectric Propulsion refers to on - air generated electric
power for aircraft propulsion
– Turboelectric generation already provides electric power for secondary systems on aircraft – Fully turboelectric propulsion means that all turbine power goes to electricity – Partially turboelectric propulsion means a turbofan engine with some fraction of generated electric power going to propulsion www.nasa.gov National Aeronautics and Space Administration
Electrified Propulsion Vehicle Trade Space
Baseline Aircraft with Podded Turbo - Fan VEHICLE CONFIGURATION EXAMPLES SCEPTOR 4 PAX X - Plane SUGAR VOLT 150 PAX Study ECO - 150 150 PAX Studies AATT 50 PAX STUDIES Current NRA 150 PAX Studies N3 - X 300 PAX Turbo - Electric STARC - ABL 150 PAX Study www.nasa.gov National Aeronautics and Space Administration
Electrified Propulsion: NASA’s Approach
Build, Test, Mature Enabling Technologies and Knowledge Bases
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Electrified Propulsion Development
Goal: Enable the paradigm shift to electric, hybrid electric, and
turboelectric propulsion for reductions in energy
consumption, emissions, and noise
Path:
• Identify promising propulsion / vehicle configurations
• Buy - down risk for crucial technologies in
• Flight Control: new knobs in vehicle and subsystems
• Power Conversion: electric machines & electronics
• Power Control: vehicle electric grid management
• Fundamental Enablers: materials and analysis
• Demonstrate results in purpose - built flight
demonstration
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Multiple Paths to Carbon Reduction
All Electric, Hybrid Electric, Turbo Electric,
Distributed Propulsion Distributed Propulsion
• On Demand Mobility Focus • Low Carbon Propulsion
• Small Plane Focused • Transport Class Focused
Enable New Aero Enable New Aero Efficiencies Efficiencies High Efficiency Power Power Sharing Distribution Distributed Thrust Power Rich C ontrol Optimization Certification Non - flight Critical Trailblazing First Application Energy & Cost Efficient, Energy & Cost Efficient, Short Range Aviation Transport Aviation www.nasa.gov National Aeronautics and Space Administration
Convergent Aeronautics Solutions Project
Aircraft Hybrid/Electric Propulsion Activities
• M - SHELLS – Multifunctional Structures for High Energy Lightweight Load - bearing Storage – Integrates hybrid battery/ supercaps into aircraft structure to increase effective specific power & specific energy – Converges advanced electrochemistries , microstructures, manufacturing, and nano - technologies • LION – Integrated Computational - Experimental Development of Li - Air Batteries for Electric Aircraft – Investigates “electrolyte engineering” concepts to enables Li - Air batteries with high practical energy densities, rechargeability and safety – Converges advances in predictive computation, material science, and fundamental chemistry • HVHEP – High Voltage Hybrid Electric Propulsion – Variable - frequency AC, kV, power distribution with DFIM machines for multi - MWe DEP applications – Minimizes constituent weights of power electronics, TMS, and fault protection • Compact High Power Density Machine Enabled by Additive Manufacturing – 2 to 3x increase in specific power of electric machines for DEP enabled by additive manufacturing – Compact, lightweight motor designs/topologies, integrated cooling, and multi - material systems/components .
• DELIVER – Design Environment for Novel Vertical Lift Vehicles – cryo - cooling HEP task – Maximizing efficiency and power density of electronic components by cryogenic LNG - fuel cooling – Longer - range hybrid/electric UAS with reduced fuel - burn and emissions (CO2, sulfur, particulates ) • FUELEAP – Fostering Ultra - Efficient, Low - Emitting Aviation Power – GA aircraft / early - adopter application of JP - fueled SOFC power plant for clean, hybrid/electric architecture – Zero NOx electric power production at ~2x typical combustion efficiencies • SCEPTOR – Scalable Convergent Electric Propulsion Technology and Operations Research – Seeks 5x reduction in cruise - energy - use by aerodynamic benefits of DEP & batteries in place of engines – DEP enables high efficiency wing & high performance wingtip motors for cruise www.nasa.gov National Aeronautics and Space Administration
SCEPTOR X - 57 Research Objectives
NASA SCEPTOR Primary Objective
• Goal: 5x Lower Energy Use (Comparative to Retrofit GA Baseline @ 150 knots) • Motor/controller/battery conversion efficiency from 28% to 92% (3.3x) • Integration benefits of ~1.5x (2.0x likely achievable with non - retrofit)
NASA SCEPTOR Derivative Objectives
• ~30% Lower Total Operating Cost (Comparative to Retrofit GA Baseline) • Zero In - flight Carbon Emissions
NASA SCEPTOR Secondary Objectives
• 15 dB Lower community noise (with even lower true community annoyance).
• Flight control redundancy, robustness, reliability, with improved ride quality.
• Certification basis for DEP technologies.
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Adv. Air Transport Technology Project Investment
Integrated Vehicles and Concepts Evaluation Efficient, Low Noise Propulsors Boundary - Layer Ingestion Systems Highly Efficient Turbine Engines Power Systems Architectures Advanced Electrical Components www.nasa.gov National Aeronautics and Space Administration
Adv. Air Transport Technology Project Investment
Objective Key performance parameters and threshold level requirements for gas turbine aircraft augmented with electrical powertrain Scrutinizing tube & wing architectures Propulsion System Conceptual Design – Concepts for system interaction exploration Integrated Subsystems – Flight control methodology for distributed propulsion Revolutionary system testing High Efficiency/Power Density Electric Machines – Step change in component performance Superconducting and ambient Flight - weight Power System and Electronics machines – High voltage power electronics, transmission, protection, and management Enabling Materials – Insulation, Conductors, Magnetic Materials Transitioning materials from lab to component www.nasa.gov National Aeronautics and Space Administration
NASA Electrified Propulsion Takeaways
• NASA Aeronautics Strategic Thrust 4 - Transition to Low - Carbon
Propulsion is supporting investment in alternative aircraft
propulsion including electrified aircraft propulsion
• The NASA vision includes transforming aviation via new propulsion
technologies integrated with airframes to
– increase aircraft functionality – reduce carbon emissions – improve operational efficiency and reduce noise
• There are many possible Electrified Aircraft configurations
• NASA investment includes vehicle concepts and technology to
support aircraft for
– Small to midsize aircraft to increase mobility provide a new paradigm – Commercial transport aircraft to impact the current large carbon producing market segment www.nasa.gov National Aeronautics and Space Administration
Timeline of Machine Power Relevant to Aircraft Class
Largest Electrical Machine on Aircraft Superconducting Non - cryogenic 100 kW 1 MW 3 MW 10 MW 30 MW 9 S eat 0.5 MW Total Propulsive Power 50 - 250 kW Electric Machines 19 S eat 2 MW T otal Propulsive Power .1 - 1 MW Electric Machines 50 Seat Turboprop 3 MW Total Propulsive Power .3 - 6 MW Electric Machines 50 Seat Jet 12 MW Total Propulsive Power .3 - 6 MW Electric Machines 150 S eat 22 MW Total Propulsive Power 1 - 11 MW Electric Machines 300 S eat 60 MW Total Propulsive Power 3 - 30 MW Electric Machines PS – 01758 – 1115 www.nasa.gov