NASA envisions a future where supersonic airliners and highly efficient aircraft all fly in the same ultra-safe skies.
And the agency is already sprinting toward that end goal by developing the X-59 QueSST and exploring alternative aircraft propulsion systems that can reduce costs, noise, and emissions.
“Our program develops technologies that help NASA and industry change the paradigm of aviation by opening the way to everyday supersonic flight, environmentally sustainable transport-class aircraft, and widespread advanced air mobility vehicles,” said James Kenyon, NASA’s Advanced Air Vehicles Program director.
NASA can’t change the future of flight alone, so the agency has teamed up with two industry partners to transform its approach to aircraft propulsion. These agreements are aimed at designing more efficient aircraft engines, while also addressing several technical challenges: weight, power extraction and storage, and thermal management.
The power extraction challenge is especially important for future hybrid-electric aircraft concepts where the energy requirement becomes even greater, as extra power is needed to drive electric fans used for additional inflight thrust.
Through its Hybrid Thermally Efficient Core (HyTEC) project, NASA is aggressively pursuing next generation aircraft engines that use less fuel and produce more power, by increasing the bypass ratio. This means making the fan – the one on the front of the engine – bigger, thereby increasing airflow, while shrinking the engine’s core which reduces fuel consumption.
“The question becomes how do we shrink the core of the engine, while maintaining performance and increasing the electric power available?” said Tony Nerone, HyTEC project manager at NASA’s Glenn Research Center in Cleveland. “As aircraft become more electric, we’ll need to address the traditional power needs – running subsystems like flight controls, air conditioning, and so on – but we also need to tap more power for the newer electric systems that we’ll be adding to the aircraft. Current state-of-the-art engines can extract about 5% of power and we’ll need to jump up to 10 percent to 20 percent in the future.”
Through a Space Act Agreement with Honeywell, NASA engineers will work with a team from Honeywell, to perform technology development and testing on an advanced low-pressure turbine. The data from the test will allow the combined engineering team to establish a turbofan power extraction baseline while also developing computational prediction tools. Ultimately, this test will provide essential data for the HyTEC project and advance Honeywell’s technology development of higher efficiency turbines that could impact its future gas turbine product line.
NASA has also entered into a contract with GE to demonstrate and assess turbofan power extraction and integrating electric machines like motors and generators. The goal is to significantly increase power extraction at relevant commercial engine operating conditions from a thrust, weight, efficiency, operability, and durability for future electric propulsion systems.
These efforts aim to introduce cleaner, more efficient and cost-effective aircraft propulsion in the near future. Core power systems technology development and testing are just the start. NASA will need to demonstrate the benefits in flight before eventual commercial aircraft integration.
“Once HyTEC and its partners demonstrate power extraction, these new engines can be combined with other megawatt-class components we’re developing for electrified aircraft propulsion,” said Barbara Esker, AAVP’s deputy program director. “Together with advances in high-rate composite aircraft manufacturing and innovative configurations like the transonic truss-based wing, NASA can transform the long-term sustainability of commercial aircraft.”