The reason why the wing receives upward lift under the action of air currents

The principle of wing lift is the difference in air pressure caused by the difference in velocity between the airflow on the upper and lower surfaces of the wing.

Lift is the upward force. The force that makes you rise. There are many kinds of them. Generally said in the air. That is, the upward force is greater than the downward force, and its resultant force can make the object rise.

The difference in air pressure caused by the difference in lift ** in the velocity of the airflow on the upper and lower surfaces of the wing. However, the explanation of the cause of the velocity difference between the upper and lower surfaces of the wing is complicated, and the isochronous theory and fluid continuity theory used in popular science cannot fully explain the cause of the velocity difference. Two-dimensional wing theory is commonly used in the aviation community, which mainly relies on the Kuta condition, the circumference around the wing, the Kuta-Zhukovsky theorem and the Bernoulli theorem.

Lift applications. The vast majority of the lift of the aircraft is generated by the wings, the tail usually produces negative lift, and the lift generated by other parts of the aircraft is very small and generally not considered. The principle of lift is that the presence of the ring around the wing (attachment vortex) causes the flow velocity of the upper and lower surfaces of the wing to be different, the pressure is different, and the direction is perpendicular to the relative air flow.

The generation of wing lift mainly depends on the action of the upper surface suction, rather than the effect of the positive pressure on the lower surface, the suction formed on the upper surface of the wing accounts for about 60-80% of the total lift, and the lift formed by the positive pressure on the lower surface only accounts for about 20-40% of the total lift. So it cannot be assumed that the aircraft is supported in the air, mainly as a result of the impact of air from under the wing.

There will be various drags in the air when an airplane flies, and the drag force is the aerodynamic force that is opposite to the direction of the airplane's movement, which hinders the progress of the aircraft, and here we also need to understand it. According to the causes of resistance, it can be divided into friction resistance, differential pressure resistance, induced resistance and interference resistance.

The four types of resistance are for low-speed aircraft, and for high-speed aircraft, in addition to these resistances, other drags such as wave resistance are also generated.

The lift of the <> aircraft comes from the elevation angle, and the arc of the high wing produces downward pressure and forward resistance, which is Newton's third law in dynamics, commonly known as the interaction force.

1) It is the buoyancy generated by convection with air; 2) It is the kinetic energy of the fuel chemical energy that is converted into the potential energy of the aircraft through the engine. That is, the lift of the aircraft is buoyancy and potential energy.

According to Bernoulli's theorem: the faster the fluid velocity, the lower the pressure, the arc part of the wing has a fast flow velocity and low pressure, and the lower straight part of the wing has a slow flow velocity and high pressure, resulting in lift.

Air is relatively stationary without being acted upon by external forces, and pressure is normal. When still air needs to flow, there must be a force to act, and this force can be a pressure greater than normal to push, i.e. (push), or a less than normal pressure to suction, i.e. (pull). The action of these two forces seems to produce a pressure difference to do the work, but there is actually a difference.

When the air flow is subjected to thrust, the air flow stores the pressure potential energy, and with the diffusion of the pressure potential energy, the air flow energy gradually weakens from back to front. When the airflow is subjected to tension, the airflow stores the suction potential energy, and with the diffusion of the suction potential energy, the airflow energy gradually weakens from front to back.

The lift force on the wing is the centrifugal force generated by the air flow around the arc-shaped blades, and the centrifugal force creates a pulling force at the blades, pulling the blades to a higher place. Since the tensile force is generated on the surface of the blade, the potential energy is strong. If there is pressure under the blade, due to the compressibility of the air flow, it will have a buffering effect on the subsequent air flow, making the thrust action less powerful than the tensile force.

Therefore, the upper surface of the blade is designed with an arc instead of a plane, and if it is flat, even if there is no air flow below, there is no lift at a high flow velocity above. For example, you can fold a piece of cardboard into an angle, the surface of the paper is flat, hold one side of the cardboard with your hand, and blow hard into the cardboard, no matter what angle you can't feel the lift on the other half of the cardboard. When you bend the other half of the cardboard into an arc, you will feel an upward pull on the curved side when you blow it.

No, I'll tell you the simplest.

Actually, the reason is very simple.

To consider the configuration of the wing, the wing is convex at the top and straight at the bottom. When an airplane is in the air, the air is blown towards the wings, and the air is divided into upper and lower parts by the wings. The upper air passes through the convex curved surface of the wing, and the lower air passes through the straight plates.

Because the time to pass through the wings is the same, but the distance is not. , the air travels a larger distance over the wing, and the speed is greater because the time is the same. The air passes under the wing, and the distance is relatively small, so the speed is relatively small.

In this way, when a section of air passes through the wing, because the speed is not the same, the air above passes through the wing, but the lower part does not. It can also be said that there is no air above the wing, but there is still air underneath, so that the air below will flow upward.

The wings are lifted up, which creates upward buoyancy.

However, this knowledge is more correctly explained by the relationship between speed and pressure.

I'm a high school student, and I've forgotten a lot about junior high school knowledge, but it's probably right.

Thank you!!!

Sadly, I think that at a certain angle, the faster the fluid velocity, the less pressure there is.

That's the explanation.

It is thought that the air flow speed of the upper wing is faster than the air flow speed of the lower wing, so the pressure is from the bottom to the top.

The distance above is long, so the flow rate will increase and the pressure will decrease.

The following is a straight board, and there is a certain angle of attack, which can be understood as accepting the impact of the air flow, and the pressure is increased to increase the pressure difference to hold up the aircraft, and the lift can be increased by increasing the speed or increasing the attitude of the aircraft to raise the head.

After a long journey, there is no air, and if there is no air and no air pressure, it will be actively sucked over, and at the same time lead to an overall decrease in pressure, an explanation of Bernoulli's principle.