How on earth can a plane in the sky take off? What does it need to take off?

First of all, there is a certain starting speed, as well as acceleration, in the process of starting to fly diagonally upward, in fact, this force can be decomposed into a role to overcome gravity, after overcoming gravity and then accelerating upwards to fly.

With the rapid development of life technology, our travel mode has undergone drastic changes, from the beginning of the bicycle and motorcycle, to the current car, high-speed rail planes, etc., it is not an exaggeration to say that the world has been turned upside down.

In fact, airplanes mainly rely on four forces to fly in the sky, which are lift, gravity, thrust and drag. Oh my God, the force that keeps us on Earth is gravity, also known as gravity.

It is the force of attraction between objects that have mass. Will the plane also be subject to gravity? Of course, all objects on Earth are attracted to the Earth. So, everybody has gravity. Everyone has gravity, so why can't I fly when the plane can fly?

This is related to the other three forces, the most relevant of which is lift, which is the force that makes the plane rise. Actually, it's the air near the plane that lifts the plane. The wing of the aircraft.

Isn't it like wings, this special shape of the wing makes the plane start to move. The pressure produced by the air below is greater than the pressure produced by the air above. In this way, the lift force is formed.

And the faster the plane, the more lift the air generates. So, when the plane is taxiing on the runway, as long as it reaches a certain speed, it will definitely be able to fly.

You can recall that when you take off the plane, at the moment when the plane takes off, it is not necessary to produce a very fast speed, and the ears will be uncomfortable, this is because the plane has to rely on thrust to produce a very fast speed to fly, it must be the thrust of the aircraft given by the engine, the engine of the aircraft is much more powerful than that of the car, their power is greater, and the technology used is also different. For example, sometimes jet engines are used in airplanes.

It can propel an airplane forward by spraying high-velocity gas.

The last force is drag, and resistance is the force you encounter as you move forward in the air that makes you retreat. Is the force of retreat the force of pulling back legs? Because when you move forward in the air, you hit gas molecules, and they will stop you from moving forward, just like going backwards in **.

The plane must have encountered a lot of resistance when it was going so fast. Therefore, one of the main tasks of aeronautical engineers is to design something that can reduce air resistance.

of the aircraft.

The first main reason is that the airplane has a unique flying device, and the second reason is that the airplane has a balance system, so it can fly around in the sky, which is the research when making the airplane, and the main process is to fly like a bird, which is mainly to study the balance of the bird.

The main reason why an airplane can fly in the sky is that the engine jet propels the aircraft, and under the propulsion of the engine, it relies on the physical principle of relative speed, so that the aircraft can fly into the sky.

Airplanes are able to fly in the sky because their own engines generate kinetic energy, which then generates lift through the wings, so that they can fly in the sky.

Mainly because the wings of the aircraft, propelled by the engine, can generate lift and fly.

Airplanes are aerodynamically liftedWhen an airplane is in the air, it undergoes aerodynamic forces that act on the aircraft. Aircraft take off and land according to aerodynamics. First of all, we should also grasp the characteristics of gas fluidity, that is, the basic law of gas fluidity.

The law of fluid continuity: when the fluid continues to pass smoothly through the pipeline with different wall thicknesses, because all parts of the fluid in the pipeline cannot be terminated or squeezed, the quality of the fluid injected into all parts is the same as that of the fluid discharged from the other part. Bernoulli's theorem deals with the interrelationship between flow velocity and working pressure in fluid fluidity.

The basic content of Bernoulli's theorem: when the fluid moves in the pipeline, the working pressure is lower in the area where the flow speed is relatively large, and the working pressure is greater in the area where the flow speed is smaller. The vast majority of the lift of an aircraft is caused by the wings of the aircraft, and the tail of a car usually causes negative lift.

The rest of the aircraft usually does not take lift into account.

Hazards of Flyout Speed and Density of Air to Resistors The greater the flyout speed, the greater the lift and drag. Lift and drag are positively correlated with the square meter of the flight speed, i.e., the rate is increased by two times as much as before, and the lift and drag are increased by four times as much: the rate is increased by three times as much, and the win and drag are increased by nine times as much.

The density of the air is large, the aerodynamic force is large, and the lift and drag force are of course great. The density of the air is doubled, and the lift and drag are also doubled, i.e., the lift and drag are positively correlated with the density of the air.

Aircraft landing is a whole process of activity that reduces the relative altitude and velocity of aircraft. When the aircraft lands from a certain relative altitude, the car engine is in a slow running state, that is, the small accelerator pedal is generally lowered. When the flight altitude of the aircraft is reduced to close to the floor, it is important to drive the safety control stick at a certain relative altitude to make the aircraft go from lower to smoother.

This is called "flattening". With the development of new technologies, aircraft wings are getting smaller and smaller, and because the technical characteristics of aircraft and automobile engines have been sufficiently excellent, aircraft can be allowed to use small wings.

Through a series of optimized structures, the aircraft's wings are reduced to bring a lot of lift. This kind of large lift also plays a greater role in the landing of the aircraft. In the process of the aircraft slowly turning off the car engine, because of the presence of the wings, the aircraft still has enough lift to support it.

Therefore, it is not easy for the aircraft to be turned off vertically like a steel block. In addition to this, the application of this type of hydrostructural mechanics can also change the orientation of the aircraft. When the tail of the aircraft changes its angle of view, the fan also changes direction, thus completing the turning of the aircraft.

The principle of aircraft take-off: take-off, along with the thrust brought by the engine, gives the aircraft a speed of rapid forward motion, so that the air and the aircraft have relative motion.

The principle of aircraft landing: landing, is to reduce the thrust of the engine, so that the speed of the aircraft is reduced, thereby reducing the speed of air flowing through the wings, thereby reducing the lift, so that the aircraft is lowered.

It depends on the air flow and air pressure to be able to fly in the sky. When landing, the speed of the flight will be reduced, and the flight altitude will also be reduced, so that the landing can be achieved.

Airplanes rely on engines and air to power to fly in the sky; The power will gradually decrease when landing.

The cross-section of the wing of an aircraft is generally rounded and blunt at the front and sharp at the rear, with an arched upper surface and a flat lower surface. When equal mass air passes through both the upper and lower surfaces of the wing, different flow velocities are formed above and below the wing. The velocity of air passing through the upper surface of the wing is high and the pressure is small; When passing through the lower surface, the flow velocity is small and the pressure is strong, so the aircraft will have an upward resultant force, that is, the upward lift, due to the existence of lift, so that the aircraft can leave the ground and fly in the air.

The faster the aircraft flies and the larger the wing area, the greater the lift generated.

The direction of gravity is the opposite of lift, it is a downward force caused by the gravitational pull of the earth, and the magnitude of gravity is affected by the weight of the aircraft itself and the amount of fuel it carries. The pulling force causes the aircraft to fly forward in the air, and the power of the engine determines the amount of pulling force. In general, the greater the engine output, the greater the thrust generated and the faster the aircraft can fly.

When the aircraft is in the air, it is hindered by atmospheric molecules in the air, and this obstacle forms a drag force that is opposite to the direction of the pulling force, limiting the flight speed of the aircraft.

Find a book on "fluid mechanics" and read it, it's too hard to talk about here.

The flow velocity of the upper and lower surfaces of the wing is different, the upper surface has a faster flow velocity and less pressure, and the lower surface has a slower flow velocity and greater pressure, which generates an upward force, so it can fly.

In rain, snow or foggy weather, the plane cannot take off normally, because it will cause blurred vision and weak communication signal. It can be dangerous, especially if we can see on the surface that the weather conditions are very bad, then the environment at high altitude will be even harsher and the safety will be reduced.

Aircraft cannot take off in bad weather such as heavy rain, heavy snow, sandstorms, tornadoes, fog, etc., because safety cannot be ensured and losses may be caused, so they cannot take off.

The aircraft is not allowed to take off during thunderstorms, low clouds, low visibility, low-altitude windshear, atmospheric turbulence, jet streams, and icing. In this case, taking off can easily cause a flight accident.

The weather when the plane can take off should be sunny and the visibility should be high. If there is heavy fog, or bad weather such as sandstorms, snowstorms, typhoons, etc., the plane cannot take off. Because of forced take-off, there are potential safety hazards, posing a threat to the personal safety of passengers and crew.

Fog and haze can reduce visibility and affect flight, and if visibility is less than 50 meters, the plane cannot even taxi, and thunderstorms are one of the worst and most dangerous weather planes can encounter in flight.

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.

The airplane relies on fuel combustion to release heat, and the heat is converted into power, which is the part of power that pushes the plane to fly.

First of all, let's explain the pressure difference: let's take a simple example, when you drink water with habits, you can feel the pressure difference, how does the water get in? When we suck water, we suck the air in the tube into a vacuum state, and the external pressure is stronger than the pressure in the tube and presses into our mouth.

02 Okay, now I can tell you that the plane flies up by the pressure difference, and the pressure difference is formed by the wing, please look at the structure of the wing, so how is the pressure difference formed?

03 The answer is that the air flow up and down the wing is different, which is determined by the different speed up and down, we all know that speed is equal to the distance divided by the time.

04 Looking at the wing structure in step 2, we can see that the distance on the upper side is greater than the distance on the lower side.

05 Then in the same time, the speed of the upper side will be greater than the speed of the lower side.

06 Then the air flow on the upper side will be faster than the lower side, if the speed of the plane is large enough, the air on the upper side will be very thin than the lower side, the density of the lower side is large, the pressure will be greater than the upper side, and the plane will take off.