Pratt & Whitney Canada Begins Ground Testing for 30% More Efficient Hybrid-Electric Aircraft
Hybrid-Electric Aicraft Engine Targeting 30% Fuel Efficiency
We have started ground testing the flight-standard propulsion system for the RTX Hybrid-Electric Flight Demonstrator in Longueuil, Quebec. This system combines an advanced thermal engine with a 1-megawatt electric motor to boost efficiency during demanding flight phases. Our goal is to prove up to 30% fuel savings on a Dash 8-100 test aircraft, with the first flight scheduled for 2027.
Assembling the final, flight-standard propulsion system brings us one step closer to proving hybrid-electric technology in flight.
- Someone
Not “30% fuel efficiency”, but an improvement of 30%.
FTA: “The project aims to demonstrate up to 30% improved fuel efficiency for a typical 250-nautical-mile regional turboprop mission”
- avidiax
I think there are startups making a similar sort of engine for general aviation. It's good to see that there is development of the same idea for commercial aviation.
This isn't like a hybrid car. It's a parallel hybrid, where the gas engine is just big enough for efficient cruise at altitude, and the electric motor/generator provides extra power for takeoff and ascent (or go-around power), and then charges slowly during cruise if needed.
This means that the battery is quite small and light, having only enough charge to take off and get to altitude.
I suspect that this system probably improves safety as well, if architected properly. If one or both of the gas engines fail, so long as they are not seized, that electric motor can still provide some power for diversion.
- _diyar
This is very clever: instead of focusing on electric only flight, just make the existing engine fly in the most efficient window while the electric engine buffers the flight profile.
Like a big-boy prius.
- tgtweak
Rtx has an interesting patent [1] on this that highlights some of the novelties of this setup vs a traditional hybrid (planetary motor/generator like in a Prius):
It's a boost-only motor, it doesn't/can't harvest energy on descent.
The patented solution (transient smoothing under auto-throttle control) puts electric motors on both the low spool and high spool, then uses a power-splitting algorithm to route high-frequency thrust changes to the electric motors while keeping fuel flow nearly constant on the thermal engine (turbine). The turbine cruises at a steady operating point with tight compressor/turbine clearances and the electric motor smooths out the spikes that are normally there with turbulence and load changes. Benefits: lower fuel burn, longer turbine life (fewer blade-rub risks from speed variation), and smoother ride quality since the auto-throttle bandwidth improves. This setup (based on the various cutaways and photos so far) seems to be only a single 1MW motor so it only runs on the low spool but can still help modulate the turbine decently in the same way it does in the Koenigsegg Regera's hybrid electric setup, that removes the need for a flywheel because the electric motor can smooth out the gas motor's inherent lumpiness.
Also disclosed in a previous press release [2], it's only a 200kWh battery so at 1MW peak boost (cited load during takeoff/ascent) it would only run for ~10-15 minutes at the beginning of the flight.
Seems most of the savings are due in p […]
- soperj
Only AI stories show up now, so they had to call it an Ai craft I guess.