Document
Sean Clarke, P.E.; Yohan Lin; Kurt Kloesel; Starr Ginn NASA Armstrong Flight Research Center 14th AIAA Aviation Technology Conference Transformational Flight - Electric Propulsion Development and Testing Wednesday, June 18, 2014 Enabling Electric Propulsion for Flight Hybrid Electric Aircraft Research at AFRC National Aeronautics and Space Administration www.nasa.gov Challenge goals will require non- traditional approaches to aircraft efficiency at both the component and system levels. Incremental improvements to existing architectures won’t be sufficient to meet these targets. Solutions will integrate new technologies and techniques from many fields (propulsion, structures, controls, etc.).
N+3=2025*** Technology Benefits -71 dB better than -75% better than -70% exploit metroplex* concepts N+2=2020*** Technology Benefits Relative To A Large Twin Aisle Reference Configuration -42 dB -75% -50%** -50% N+1=2015*** Technology Benefits Relative To A Single Aisle Reference Configuration -32 dB -60% -33%** -33% x CORNERS OF THE TRADE SPACE Noise (cum below Stage 4) LTO NO Emissions (below CAEP 6) Performance: Aircraft Fuel Burn Peformance: Field Length *** Technology Readiness Level for key technologies = 4-6 ** Additional gains made be possible through operational improvements. * Concepts that enable optimal use of runways at multiple airports within the metropolitan area
ARMD Goals for System Level Metrics (last updated in 2010)
Armstrong Flight Research Center 3 3 3
2 MW Testbed
Iron Birds
Advances
Motor Generator
Advanced Flight Testbed Or Experimental Vehicle
Hardware-in-
the-Loop Sims
Airvolt Hybrid Airvolt Hy
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es es es es R R R R R R ht ht ht ht ht ht h
Airvolt
g ig ig ig i i Fl Fl Fl F Fl strong
EIST LEAPTech EIST LEAPT
The Big Picture / Elec. Prop. Research Pathway at AFRC
HEIST LEAPTech
HEIST PMAD
Armstrong Flight Research Center : System design and implementation standards needed: : Unexpected complexities surface on flight-like systems: : Limited budgets in aeronautics R&D drive a spiral development approach : Components are needed at higher energy/power density and smaller volume Will DC buses remain stable with high-frequency loads? What grounding issues will only emerge when airframe installation compromises are considered? Will EMI/EMC effects emerge in volume/weight constrained applications? What measurement techniques and sensor technologies are necessary or ideal? What V&V methodologies are most effective? What physics-based issues/phenomena cannot be predicted with simulation? How should subsystem performance be monitored? How will thermal management become a design driver at high power density? How will battery management and quality be affected by high energy density systems? How can we achieve the most research objectives with limited budgets?
System Integration › › › Standards Development › › › › Size › › Funding ›
Challenges to Advancing Electric Propulsion System TRL
Armstrong Flight Research Center 5 5 Size SysInt Funding Challenges Standard (200 kSPS) (200 kSPS) (100 SPS) (5 kSPS) (100 SPS) (measured at 5 kSPS) : Up to 120 fps : up to 500 VAC, 500 A : up to 3,000 rpm : up to 40 kW : up to 500 VDC, 500 A : up to 6' diameter : -50 to +150 ft-lbs : Up to 500 lbs , Temp, Humidity BARO Motor Power ECU Power Thrust True Air Speed Torque P Motor Speed Propellers Total power
AirVolt: Single String Propulsion Test Stand
Armstrong Flight Research Center Size SysInt Funding Challenges Standard Allison 250 turbine Motor & Controller Batteries and BMS Batteries and BMS Investigate power transfer stability challenges Initial concept reviews complete. Targeting 317 HP/230 kW config Major System Components › › › › ong Flight Research Center
Hybrid Airvolt
Armstrong Flight Research Center Size SysInt Funding F Challenges Standard S S Measure real flow physics associated with the proposed configuration Develop phase 2 test objectives for higher fidelity test points and measurement goals First experiment to be conducted at Armstrong, Nov 2014 Funded by ARMD Team Seedling competition (partnership between AFRC, LaRC, ARC, GRC) Obtain data to validate CFD tools for designing and optimizing distributed propulsion configurations Leading Edge Asynchronous Propeller Technology (LEAPTech): › › ›
Hybrid-Electric Integrated System Testbed (HEIST)
Armstrong Flight Research Center Size SysInt Funding Challenges Standard Top level engineering Instrumentation System Integration Wing Manufacturer Motors, motor speed controllers, propellers Test Rig (truck platform) fab, force balance design
ESAero-Small Business Contractor (Prime) › › › Joby Aviation (Subcontractor) › › ›
Oversight / Host Requirements Management Master motor controller Test Execution Safety Review Process LEAPTech lead (PI) Wing aero design CFD analysis Structural analysis
NASA AFRC › › › › › NASA LaRC › › › ›
LEAPTech: Major Roles & Responsibilities
Armstrong Flight Research Center Size SysInt Funding Challenges Standard Second experiment on the HEIST, Feb 2016 Static propulsion test stand co-located with Airvolt Evaluate inherent issues with parallel-hybrid electrical bus architecture (bus stability given many dynamic loads and sources) Characterize aggregate thrust control of many motors in parallel (including coupling effect and reaction to motor-out scenarios) Research control approaches for integrating hybrid-generator Investigate algorithms for thrust augmented yaw control Assess power generation/consumption problems (incl. catastrophic load shedding)
Power Management and Distribution (PMAD): › › › › › › ›
Hybrid-Electric Integrated System Testbed (HEIST)
Armstrong Flight Research Center Size SysInt Funding Challenges Standard : A novel controller will be developed to : A research flight control : A control algorithm will be developed that will manage : A control algorithm will be developed that will Distributed Propulsion Electronic Controller translate the thrust targets with simulated pilot inputs into individual thrust commands for each of the propulsors (Propulsive Yaw Control, expanded take-off vertical speed envelopes). This controller will also need to manage the balance between power generation, storage and consumption of this electrical propulsion system Power Management Algorithm the loading of the power generator, the real-time capacity of the energy storage buffer (e.g., battery system) and the power demand of the collection of propulsors. Thrust Distribution Algorithm synthesize individual propulsor commands based on the total system thrust targets established by the pilot and the generator and stored power availability. Apply advanced control strategies (Peak Seeking Controller). Embedded Flight Control Computer computer will be developed to host the hybrid electric distributed propulsion control algorithms
HEIST: Power Management and Distribution Research
Armstrong Flight Research Center
: Include control surfaces, flight-
:
: Integrate flight-like electric propulsion
Derive models of power system component performance Formulate more detailed requirements for these complex systems based on lessons learned on initial tests Build more advanced data acquisition and analysis systems Hardware in the Loop system hardware into simulated electric aircraft flight controls, real- time feedback on component loading (dynamometers) Aircraft in the Loop / Ironbird ready control system, flight-like energy storage components Based on initial teststand data › › › Simulate flight environments and mission constraints › ›
Pathway to High Fidelity Simulators
Armstrong Flight Research Center Real-world volume and weight constraints Address failure modes and recovery strategies Identify and resolve interdependencies between propulsion and other systems Validate aero-propulsive efficiency gains over traditional propulsion/airframe designs Demonstrate realistic performance benefits due to propulsion airframe integration Increase electric vehicle technology readiness Identify key multidisciplinary integration challenges Enable industry partners use of these lessons as a springboard for accelerated commercial development.
1-2 MW vehicle; modular architecture to allow for multiple configurations (TeDP / Hybrid / All-electric; serial or parallel buses) Address actual implementation effects: › › › › › This coordinated research and development strategy will: › › ›
Modular Electric Propulsion Flight Test Platform
Armstrong Flight Research Center Model/ Seedling 6DOF Aero Boundary efficiency Phase II Layer Ingestion
LEARN/RHRC
Hybrid Electric
Simulator w/HIL
Propulsion Flight
HEIST Ground Test Data/Airvolt/ A/C Study Conversion Tech/NPSS GRC/Georgia
STTR/RHRC
HEIST Phase III ePHM Phase II
SBIR/ESAero/GA
Controller Propulsion Distributed Adjacent Interaction Propulsor Inlet Phase II Turbo- generator PMAD and Feedback Instrumentation
SBIR/METIS
handling Generator vs Battery transient Dynamic Propulsor Performance Hybrid- Electric
Airvolt Ai A
g Flight Research Center System
Hybrid Electric Propulsion Research Collaboration
Single String Distribution High Voltage Efficiency Armstrong Flight Research Center
HEIST - TeDP
14 14 Stator (Printed Circuit Board) ram ram ne ht ; builds on a two-spool turbine Rotor (axial layout with N52 Nd magnets)
SBIR: Lightweight Small-Scale Turbine Generator
Metis Design Corporation concept demonstrated on the DARPA Transformer program Objective is to perform a preliminary design a lightweight turbine generator and demonstrate the key innovative elements of the generator concept (40 kW) So far: intermediate-speed testing has been performed (16 krpm, 50% full speed) to improve modeling of the system losses Phase II kickoff June 2014 Armstrong Flight Research Center
Hugh L. Dryden
—
[The purpose of flight research] is to separate the real from the imagined problems and to make known the overlooked and the unexpected.