10 ms·
>Electric engines have a significantly better trust-to-weight ratio. Aerospace engineer here. This is not accurate, unless you are perhaps discussing cars. B
by na85 6y ago
>Electric engines have a significantly better trust-to-weight ratio.
Aerospace engineer here. This is not accurate, unless you are perhaps discussing cars. But for aircraft the torque supplied by the motor is not nearly so critical.
First of all propeller thrust is a function of airspeed, and it falls off significantly as you accelerate, irrespective of whether your powertrain is electric or hydrocarbon. This is a direct consequence of physics that can't really be avoided and it's why we usually talk about propeller aircraft as being "power producers" rather than "thrust producers". Propeller horsepower is much easier to reason about, and more relevant to the performance of the aircraft, than torque.
I'm not aware of any electric-powered turbojets/turbofans beyond the prototype phase but they would theoretically have better static thrust properties by virtue of not being props rather than any particular property of electric motors.
- nickik 6y agoI stand corrected. Just to be clear for my understand, would this not only be true during optimal cruise? Outside of optimal operation, specially during the start, this would actually be an advantage of electric motors? I was looking into the potential of electric turbofans. I'm just happy you didn't shoot everything down.
- na85 6y ago>Outside of optimal operation, specially during the start, this would actually be an advantage of electric motors? When you say "this" do you mean "having more low-end torque than a gasoline motor"? In theory, you could tune your prop governor to take a bigger "bite" of the air at low airspeed and thus perhaps get better acceleration and a shorter takeoff roll. But aircraft performance is very rarely limited by the torque output of the engine itself. Usually the driveshafts and gearboxes are the limiting factors in power/torque transmission.