Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid-Wing-Body Aircraft
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Citations
Retrospect and prospect of electric airplane in the propulsion system, energy storage and supply system
Coupled electromagnetic and structural analysis of support structures for the main rotor electric motor of a hybrid helicopter
Electromagnetic-Component-Coupled Performance Analysis of Future Turboelectric Aircraft Propulsion Systems
Electric Aircraft Fueled by Liquid Hydrogen and Liquefied Natural Gas
Far-Term Exploration of Advanced Single-Aisle Subsonic Transport Aircraft Concepts
References
Review of high power density superconducting generators: Present state and prospects for incorporating YBCO windings
Development status of rotating machines employing superconducting field windings
Airframe Design for "Silent Aircraft"
HTS machines as enabling technology for all-electric airborne vehicles
Analysis of fields and inductances in air-cored and iron-cored synchronous machines
Related Papers (5)
Frequently Asked Questions (20)
Q2. What is the pitch effector for a turbine?
Pitch effector can be made of low temperature tolerance material: Because only cold fan air impinges on it, the pitch effector does not have to be made of high temperature tolerant materials.•
Q3. What is the effect of a fan nacelle on the wing?
Since the top of the fan nacelle is likely to have laminar flow over at least a portion of it, while the fuselage that is being covered is where the turbulent boundary layer is thickest, a increasing fan nacelle length might actually decrease drag.
Q4. What is the effect of a low engine jet noise?
Minimal engine core jet noise: Designing to a low turbogenerator nozzle pressure ratio extracts the maximum amount of energy from the gas stream which has the effect of reducing the turbogenerator exhaust gastemperature and velocity and hence reduces noise.
Q5. What are the possible non-linear aircraft control laws?
Possible non-linear aircraft control laws: Being embedded in the boundary layer may cause interactions between the external aerodynamics and the propulsion system.•
Q6. What is the way to position the turbogenerators and fan modules?
The use of electrical power transmission allows a high degree of flexibility in positioning the turbogenerators and fan modules to best advantage.
Q7. What is the effect of a variable ratio gearbox?
The speed of the power turbine shaft in the turbine engine is independent of the fan shaft speed - the electrical system functions as a gearbox with an arbitrary gear ratio.
Q8. What is the role of power inverters in a turbine?
Power inverters are required to allow the speed of the fans to be reduced to match the available power while the power and speed of the remaining turbogenerator are brought to a maximum.•
Q9. Why do the authors think superconducting motors and generators are needed in large transport aircraft?
The authors feel that for large transport aircraft it will be necessary to use superconducting motors and generators rather than conventional motors and generators in the aircraft propulsion system to reduce the weight fraction of the propulsion system.
Q10. What is the advantage of a oversized turbogenerator?
The turbogenerators could be oversized with regard to the power needs of propulsion to provide significant amounts of electrical power for non-propulsion uses while in flight.
Q11. What is the optimum FPR for the inlet ram?
Rerunning the propulsion system performance study with a lower 0.943 freestream to fan face pressure ratio may result in generally higher TSFC values and a higher optimum FPR.
Q12. What is the effector's effect on the engine?
Greater pitch effector effectiveness: Blowing all the fan air over the pitch effector increases its effectiveness, allowing the pitch effector to be smaller and/or not located as far aft.•
Q13. How much power loss is required for the entire superconducting portion of the electrical system?
For the purposes of calculating the cooling required, the authors have assumed a power loss of 0.03% total for the entire superconducting portion of the electrical system.
Q14. What are the advantages of using a distributed turboelectric propulsion system with superconducting?
using a distributed turboelectric propulsion system with superconducting devices may present adverse effects in overall vehicle performance and operation.
Q15. How did the inlet flow rate and ram drag at the inlet lip be calculated?
To match the inlet mass flow rate and inlet ram drag entering the fan face at the vehicle ADP condition and to account for total pressure loss due to boundary layer build-up along airframe surface at the inlet lip location, a 1st order approximationof the boundary layer profile was obtained using simple flat plate equivalent of upper airframe surface by matching assumed total pressure loss of N2A configuration and mass flow rate entering the current N3-X inlet.
Q16. What are the advantages of a distributed turboelectric propulsion system?
The generators, motors, inverters, and the balance of the superconducting system may weigh more than a mechanical gearbox that accomplishes some of the same tasks as the turboelectric system.•
Q17. What is the way to reduce turbogenerator noise?
If turbogenerator noise remains too high for an exposed mounting location, the turbogenerator can readily be moved elsewhere on the aircraft without disturbing the fan nacelle location or operation.•
Q18. What is the TSFC curve for embedded engines?
the higher losses for the embedded installation compared to a pylon mount with a pitot inlet means that the bottom of the TSFC curve for embedded engines is likely to be at a higher FPR than for a podded, pylon mounted engine.
Q19. How much methane flow is required for cooling?
Given this loss level, the methane flow rate required for cooling is approximately 17% of that required to fully power the aircraft with methane.
Q20. What is the way to reduce the AC losses in HTS materials?
The several types of AC losses that occur in HTS materials can be reduced by reducing the size of HTS filaments in the composite conductor and twisting them.