How Planes fly - Really!
How planes fly isn't perfectly understood. You would think it was a settled topic, but there is disagreement, or at least competing dogma.
In grade school you were taught about faster speed above the wing and difference in pressures.
Well that is part of the story.
A wing that doesn't send the majority of the turned airflow downward creates no lift. It merely is riding through the air in whatever direction the powerful engine will push it.
In high lift wings such as a wing with flaps deployed, a majority of the turned airflow is sent downward in relation to the zero degree stabilizer. Newton tells us that any force must be balanced with an equal force in the opposite direction. For every action, there is an opposite reaction. Airflow downward, wing up.
For a complete picture of how a plane flies, you need to consider that Bernoulli and Coanda are talking about the same thing, just in different ways. A wing will fly upside down if the angle sends air downwards in relation to the stabilizer.
Turning the air downward is accomplished with wing angle, airfoil or both. Stick your hand out the car window and feel the force exerted as you turn the angle. Same thing with a wing.
Stability in the air is established by opposing forces. It is difficult to water ski if the skis are parallel to the water because the skis need more drag behind the skier's balance point. Lean too far back and the skier falls, lean too far forward and the skier falls over the ski tips. Same thing with a plane and nearly the same angles.
In grade school you were taught about faster speed above the wing and difference in pressures.
Well that is part of the story.
A wing that doesn't send the majority of the turned airflow downward creates no lift. It merely is riding through the air in whatever direction the powerful engine will push it.
In high lift wings such as a wing with flaps deployed, a majority of the turned airflow is sent downward in relation to the zero degree stabilizer. Newton tells us that any force must be balanced with an equal force in the opposite direction. For every action, there is an opposite reaction. Airflow downward, wing up.
For a complete picture of how a plane flies, you need to consider that Bernoulli and Coanda are talking about the same thing, just in different ways. A wing will fly upside down if the angle sends air downwards in relation to the stabilizer.
Turning the air downward is accomplished with wing angle, airfoil or both. Stick your hand out the car window and feel the force exerted as you turn the angle. Same thing with a wing.
Stability in the air is established by opposing forces. It is difficult to water ski if the skis are parallel to the water because the skis need more drag behind the skier's balance point. Lean too far back and the skier falls, lean too far forward and the skier falls over the ski tips. Same thing with a plane and nearly the same angles.
How does the skier stay up and not sink. At a certain speed the fluid becomes more like whipped cream and will support the weight of the skier. A plane moving fast through air reaches a point where the air becomes more dense and will support the weight. Slow down and the plane sinks. Speed up and the plane rises.
As a plane turns one wing is moving faster through the air, one slower. This would normally cause a plane to continue rolling and would require an opposite control by the pilot to level. With a plane that has dihedral and upturned tips this causes the plane to have more upward lift on the
slower wing to balance the faster moving wing. The weight of the plane being under the wings will drop the plane to level flight without pilot input.
slower wing to balance the faster moving wing. The weight of the plane being under the wings will drop the plane to level flight without pilot input.
A low wing plane with dihedral will have most of its weight above the wings but be somewhat tamed by the pendulum effect of the dihedral. A sport plane with a symetrical wing at midpoint will go wherever the pilot points it and will continue in that direction until the pilot redirects. A beginner plane will fly itself and return to level flight without input from pilot.
A plane's motor will swing counterclockwise, and Newton tells us the plane will want to turn clockwise. This will cause the right wing to fly faster through the air and create more lift and the plane will tend to turn left. To counter this we put right thrust relative to the centerline so while the plane is trying to turn left, it is also trying to turn right.
Just like with water skiing, if we create more drag at the rudder the skis will tend to turn in the opposite direction. Everything happens around the CG (center of gravity). And with a plane the wing moving fastest through the air will rise more creating the banked turn.
