Deep ocean sailing yachts used to use these for electricity generation (for powering things like navigation equipment and radios) but now it's more common to use battery backed solar power.
The power comes much more from the wind than the vehicle moving through the air (though I am very aware that the speed of the boat affects the apparent wind the generator will experience)
They make an horrific noise when deployed, the blade tips are highly supersonic. I've heard one once as a groud observer and I can only imagine the racket they make in the cabin. For that reason they're not tested in routine service but there are ground-testing rigs that spin them up to a fraction of their maximum rotation speed.
The A320 series have RATs but the 737s ( all series ) don't since they remain manually-flyable without electrical power.
It looks like a turbine powered by the movement of ambient air, in this case due to the aircraft's movement through said air.
But the article says:
The RAT generates power from the airstream by ram pressure due to the speed of the aircraft.
How is this dependent on the pressure, rather than just the speed of the air? Would a RAT from an aircraft not work on a stationary object subject to wind? Or is such an object also experiencing ram pressure (just the other way around due to reference frame shifting), i.e. all (wind) turbines work due to ram pressure?
Aerospace eng. here, you are right in that is a confusing terminology. Ram pressurein this context is a way to refer to the available kinetic energy due to airflow: 1/2 x density x speed^2 (also called dynamic pressure).
A point to stress is that the energy delivered to the plane systems by this auxiliary turbine is thus varying with the square of the speed of the plane. That means that as you slow down for landing, the RAT delivers less and less energy... and the commanding authority of the hydraulic-actuated control surface lowers, making the plane less and less controllable. Not fun!
It takes a lot of gall to double down on your mistakes in a situation like that. These two should've been stripped of their license had they survived that stunt.
It seemed like they were hoping the 2nd engine wasn't totally cashed. So they lied to the ground about having only 1 engine failure. I would imagine being alive is worth embarrassment but given the prestige of a pilot, I really can't say more than, bad choice.
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[ 2.9 ms ] story [ 47.8 ms ] threadhttps://en.wikipedia.org/wiki/Wind_turbine
The power comes much more from the wind than the vehicle moving through the air (though I am very aware that the speed of the boat affects the apparent wind the generator will experience)
http://cdn.streamlike.com/secure/Covers/68/17853.jpg
The A320 series have RATs but the 737s ( all series ) don't since they remain manually-flyable without electrical power.
It looks like a turbine powered by the movement of ambient air, in this case due to the aircraft's movement through said air.
But the article says:
The RAT generates power from the airstream by ram pressure due to the speed of the aircraft.
How is this dependent on the pressure, rather than just the speed of the air? Would a RAT from an aircraft not work on a stationary object subject to wind? Or is such an object also experiencing ram pressure (just the other way around due to reference frame shifting), i.e. all (wind) turbines work due to ram pressure?
A point to stress is that the energy delivered to the plane systems by this auxiliary turbine is thus varying with the square of the speed of the plane. That means that as you slow down for landing, the RAT delivers less and less energy... and the commanding authority of the hydraulic-actuated control surface lowers, making the plane less and less controllable. Not fun!
You don't deploy the RAT unless shit is going sideways.
We can't also confirm nor deny that RAT is a hand-picked acronym to make the "rats leaving the ship, we're doomed" joke.
https://en.m.wikipedia.org/wiki/Pinnacle_Airlines_Flight_370...
https://www.youtube.com/watch?v=FfB2EP71hqY