Why can airplanes fly, why can airplanes fly

Any aircraft must generate a lift force greater than its own gravity in order to fly into the air, which is the basic principle of aircraft flight. I believe everyone has played with kites or bamboo dragonflies when they were children, these two small gadgets are very simple in structure, but they contain profound principles of flight. The wing of the airplane comprises two kinds of fixed-wing and rotary-wing, and the principle of the kite is somewhat similar to the glider, all rely on the upward lift force that is blown by the on-demand air flow, but there is a certain difference with the fixed-wing aircraft; However, gyroplanes and bamboo dragonflies have the same effect, both rely on the rotation of the rotor to produce upward lift.

How does the wing generate lift? Let's start with a little experiment: hold one end of a piece of white paper, the other end of the white paper will naturally hang down due to gravity, and now we will take the white paper to our mouth and blow in a horizontal direction to see what happens.

Ha, instead of being blown open, the hanging end of the paper floats up, what is the reason for this? The basic principle of fluid mechanics tells us that the atmospheric pressure of the slow flow is greater, and the atmospheric pressure of the fast flow is smaller, and the air on the white paper is blown and flows faster, and the pressure is smaller than the air that does not move under the white paper, so the white paper is held up. For a fixed-wing aircraft, when it flies in the air at a certain speed, according to the principle of relative motion, the movement of the wing relative to the air can be seen as the wing is not moving, while the air flow flows through the wing at a certain velocity.

Because the wing is generally asymmetrical, the upper surface is more convex, and the lower surface is relatively flat, which makes the air be divided into upper and lower strands when flowing through the wing, the air flowing through the upper surface is fast and the pressure is small, and the air flowing through the lower surface is slow and the pressure is large, which produces a pressure difference between the upper and lower wings, and the upward pressure is the lift of the aircraft, which drags the aircraft in the air.

Airplanes can fly, relying on aerodynamic power. From the nose to the tail, the upper length of the wing is longer than the lower length. In this way, when the air flows from the nose direction to the tail, the speed of the air above the wing is higher than the speed below.

According to fluid mechanics, the higher the velocity, the lower the pressure. That is to say, the force of the air under the wing on the wing is greater than that on the wing, as long as this force is greater than the weight of the aircraft, the plane will fly under the action of the air.

The side profile of the wing is a shape in which the upper edge is arched upwards and the lower edge is basically straight. Therefore, the air flow blowing through the upper and lower surfaces of the wing and from the front end of the wing to the rear end at the same time will pass through the upper edge faster than the lower edge (because the upper edge has a large arc and a longer arc length, which means that the distance is longer). According to the Bernoulli equation of physics:

The same fluid that flows through a certain surface has less pressure on the surface at a faster speed. Therefore, it is concluded that the atmospheric pressure on the upper surface of the wing is smaller than that on the lower surface, so that the lift force is generated, and the lift force reaches a certain level, and the aircraft can lift off the ground. There's a formula I don't know if you've ever seen it:

l＝cl*1/2*ρ*v*v*s。

Summary. Airplanes fly into the sky on the principle of aerodynamics, the main of which are two fluid theorems: the continuity theorem and Bernoulli's theorem.

Most of the lift of the aircraft is generated by the wings, and the air flows to the leading edge of the wing, which is divided into two streams, upper and lower, which flow along the upper and lower surfaces of the wings respectively, and rejoin at the trailing edge of the wing and flow backwards. The upper surface of the wing is relatively convex and the flow tube is thinner, indicating that the flow rate is increased and the pressure is reduced. On the lower surface of the wing, the air flow is blocked, the flow tube becomes thicker, the flow velocity slows down, and the pressure increases.

As a result, there is a pressure difference between the upper and lower surfaces of the wing, and the sum of the pressure difference perpendicular to the direction of the relative airflow is the lift of the wing. With the help of the lift gained from the wings, the heavier-than-air aircraft overcomes its own gravity due to the Earth's gravity and soars into the blue sky.

Why do airplanes fly.

Hello dear, I'm glad to answer your questions, airplanes fly into the sky on the principle of aerodynamics.

Airplanes fly into the sky on the principle of aerodynamics, the main of which are two fluid theorems: the continuity theorem and Bernoulli's theorem. Most of the lift of the aircraft is generated by the wings, and the air flows to the leading edge of the wing, which is divided into two streams, upper and lower, which flow along the upper and lower surfaces of the wings respectively, and rejoin at the trailing edge of the wing and flow backwards.

The upper surface of the wing is relatively convex and the flow tube is thinner, indicating that the flow rate is increased and the pressure is reduced. On the lower surface of the wing, the air flow is blocked, the flow tube becomes thicker, the flow velocity slows down, and the pressure increases. As a result, there is a pressure difference between the upper and lower surfaces of the wing, and the sum of the pressure difference perpendicular to the direction of the relative airflow is the lift of the wing.

With the help of the lift gained from the wings, the heavier-than-air aircraft overcomes its own gravity due to the Earth's gravity and soars into the blue sky.