- #36
David Lewis
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I agree totally. My observations are not representative.
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The "induced power" formula actually is dimensionally correct. I don't know where the "2" factor comes from, so leaving that out and applying it to the Wright flyer data gives P = 2240 watts or about 3 hp. Their engine actually produced about 12 hp, so this formula (as pointed out) has little practical value.insightful said:Perhaps you could provide an example. For instance, the 1903 Wright flyer produced 90 lbf thrust with two 8.5 ft long propellers.
Gravity acts downwards, the aircraft is flying upwards. Gravity is reducing the achievable acceleration.David Lewis said:I counted the component of gravitational force parallel to the flight path the same as an acceleration to simplify performance calculations.
It is not, the orientation of the aircraft plays a role as well. Lift the nose and you get force between your back and the seat without any acceleration.David Lewis said:As a quick verification, when you are taking off in an airplane, the force with which the seat presses against your back is proportional to acceleration.
mfb said:Gravity acts downwards, the aircraft is flying upwards. Gravity is reducing the achievable acceleration.
Acceleration doesn't lead to much stress on the tires - they are passive anyway, unlike in cars where they transmit the accelerating force.
It is not, the orientation of the aircraft plays a role as well. Lift the nose and you get force between your back and the seat without any acceleration.
If aircraft would keep accelerating with the same magnitude after liftoff, they would reach their cruise speed within something like 2-3 minutes. That is not the case, they accelerate slowly while mainly gaining altitude.. The acceleration drops significantly after liftoff.