Why does an airplane fly?

Answer 1

A wing is usually designed with a more pronounced curve on top than on the bottom. When the wing moves through the air, air molecules traveling over the top of the wing travel farther than molecules traveling under the wing, meaning that the air on top of the wing moves faster over the surface than the air on the bottom. A scientist named Bernoulli once discovered that as the speed of air over a surface increases, the pressure of the air decreases. This is called Bernoulli's Principle. In the case of a wing, the higher pressure air under the wing tries to move to the lower pressure area above the wing, and lifts the wing. This is called LIFT. To simulate LIFT, let a piece of paper hang down just below your lips. A dollar bill works great for this demonstration. As you blow air out through your lips, the dollar bill will rise up. You have created LIFT, due to the moving air over the top having less pressure than the air below.

Airplane propeller blades also work like airplane wings and create a type of LIFT in a forward direction. If you look at a propeller from the tip of the blade, you will see that it is shaped like a wing, with a slightly more rounded area toward the front of the airplane than the back. As the propeller rotates, the blades act like wings, lifting the propeller forward. This is referred to as THRUST. As the propeller turns faster, it generates more THRUST and pulls the airplane forward.

A: Have you ever watched a big jetliner lumber into position on the runway for takeoff and wonder: "How does that thing ever get off the ground?" You know it's because of the wing that it stays up in the air, but how does it really work? Man has always watched birds as they take flight and wondered how these creatures can take to the sky while the rest of us remain earthbound. The key has always been figuring out how the wing works in lifting and propelling birds in flight. After centuries of trial and error, the Wright Brothers took their first powered, heavier than air flight in 1903. What they figured out, and what has since become a major aspect of modern civilization, is the "airfoil". The wing on an airplane is an airfoil. When air flows around the wing, it creates lift. They way it creates lift is based on the wing's movement through the air and the air pressure created around the wing. An airplane's wing, in varying degrees depending on the type and design of the airplane, is curved over the top of the wing and straighter underneath the wing. This shape is key in how lift is created as the wing moves through the air. As air hits the wing, it is "split in two", with air moving both over and under the wing. Since the top of the wing has more curve than the the bottom of the wing, the air moving over the top of the wing has further to travel, and thus must move faster than the air moving underneath the wing. The air moving over the top of the wing now has decreased air pressure than the slower moving air under the wing. Lift is created. This difference in air pressure is the primary force creating lift on a wing, but one other force exerted on the airfoil helps to produce lift. This is the force of deflection. Air moving along the underside of the wing is deflected downward. We remember that Isaac newton tells us that for "every action, there is an equal and opposite reaction". Thus, the air that is deflected downward (action), helps to push the wing upward (reaction), producing more lift. These two natural forces on the wing, pressure and deflection, produce lift. The faster the wing moves through the air and the greater the forces become, the greater the lift. The physics and math get a little more complicated when figuring just how to build a wing to produce the required lift for a particular airframe, and other components are needed to control and stabilize the airplane in flight. The components include the vertical fin, rudder, horizontal stabilizer, and elevator (which can be collectively termed the "tail" of the airplane). But all these elements, like the wing, are airfoils and operate in accordance with these basic principals of pressure and deflection as they move through the air. A propeller is also an airfoil, and it produces "horizontal" lift, pulling the airplane forward. Depending on choice of viewpoint, it can be said the airplane is drawn forward into the vacuum of a low pressure area created by the spinning airfoil we know as a propeller. (The reaction being thrust.) The wing of an airplane can also be said to induce a draw of the airplane upward into this airfoil created vacuum depending on how you care to view the pressure difference. The key to understanding more completely what an airfoil is doing is the knowledge that air it's self has a degree of mass. The more condensed the air, the more the airfoil (the wing, the prop, or the jet engine), has to work with. This is what restricts airplanes to altitudes that have sufficient air mass. So although airplanes are lifted and held up by pressure difference they ride on air mass. (jet engines are beyond the scope of this article, but they push air through their internal components at very high pressure, creating the required forward motion) As that giant jetliner rumbles down the runway, faster and faster, until it finally lifts of the ground and into the sky, you'll be secure in the knowledge that what is lifting the craft into the air are basic laws of physics. The same laws of physics that have lifted our feathered friends into the air for millions of years!

A: Airplanes are able to fly because of Bernoulli's principle. The wings are shaped so that when they are moving fast enough they create a low pressure area above the wing and a high pressure below, causing lift.

A: The way an airplane flies is based on 'Bernoulli's Principle'. This principle explains that fast moving air creates low pressure, and slow moving air creates high pressure. When an airplane flies, some of the air flows over the top of the curved part of the wings, and some go underneath the flat part of the wings. The air that flows over top of the wing is fast moving air, which is low pressure, and the air that flows underneath the wing is high pressure. Since the slow moving air that is high pressure is flowing under the wing, it pushes it up, and there is less pressure from the top, not pushing it down, thus causing lift.

A: Aircraft wings are created in curved shapes known as "airfoils" and are usually curved more on the top than the bottom. This is because when a fluid (air in this case) flows over a curved surface, it accelerates. And according to Bernoulli, when a fluid accelerates, pressure decreases. Now with the greater curvature of the upper surface of the wing than the lower, a pressure differential is created, where there is a low pressure area on top of the wing. This differential essentially sucks the aircraft upward through the air and is known as "lift".