How to get to the sky Why can the plane fly to the sky

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.

The aircraft glides from the ground to the ground and lifts off the ground as a result of the lift increasing until it is greater than the aircraft's gravity. And only when the speed of the aircraft increases to a certain point, it is possible to produce enough lift to support the gravity of the aircraft. It can be seen that the take-off of an airplane is an acceleration process with increasing speed.

The take-off process of the piston propeller aircraft with less residual pulling force can generally be divided into four stages: take-off and run, off the ground, small angle ascent (or a section of level flight), and ascent. For the propeller aircraft with sufficient residual pulling force, or the jet aircraft with sufficient residual thrust, because the aircraft can be accelerated and ascended, the take-off is generally only divided into three stages, namely the take-off, the ground and the ascent. The purpose of the take-off run is to increase the speed of the aircraft until ground clearance is obtained.

The greater the pull or thrust, the greater the residual pull or thrust, and the faster the aircraft will grow. During takeoff, in order to increase the speed as soon as possible, you should push the throttle to the maximum position.

The airplane can fly into the sky because the airplane will rely on the flow speed to generate pressure before takeoff, so that the plane has an upward lift, so the plane can fly into the sky.

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.

The landing of an airplane is similar to that of an airplane taking off. During landing, the aircraft needs to maintain sufficient lift while constantly decelerating to ensure that the aircraft can descend smoothly. When landing against headwinds, the aircraft can obtain the required lift at a lower speed, thereby reducing the relative velocity to the ground at the moment of grounding, thereby reducing the taxiing distance.

The reason why the plane can fly into the sky is mainly because of the solution of the following three problems:

power problems in order for the aircraft to have sufficient flight speed;

lift issues to generate enough lift to hold the aircraft up;

Maneuvering problems to change the attitude of the aircraft as needed to enable the aircraft to rise, turn, descend, .......

To solve the first problem, it was the installation of engines that would allow the aircraft to move forward and reach sufficient speed;

To solve the second problem, there are wings or rotors (***). The majority of the aircraft's lift is generated by the wings: the air flows to the leading edge of the wing, divides into two streams, the upper and lower airflows, which flow along the upper and lower surfaces of the wing, respectively, and rejoin at the trailing edge of the wing and flow backwards.

The upper surface of the wing is more convex, the flow rate increases, and the pressure decreases. On the lower surface of the wing, the air flow is blocked, the flow rate slows down, and the pressure increases, so that the pressure difference between the upper and lower surfaces of the wing appears, and the sum of the pressure difference perpendicular to the relative direction of the air flow is the lift of the wing. In this way, the heavier-than-air aircraft overcomes the gravity of the aircraft with the help of the lift gained on the wings and is able to soar through the air.

In order to solve the third problem, there are control devices in the aircraft, including steering sticks, pedals, elevators, rudders and ailerons. With these devices, the pilot can maneuver the aircraft to rise, turn, descend, .......

How planes fly into the sky

1.Accelerated taxi: When the aircraft reaches the take-off runway, the pilot will accelerate the aircraft to taxi, so that the flying pants will reach the take-off speed and generate lift.

3.Takeoff: When the aircraft reaches sufficient speed and lift, the pilot lifts the nose wheels of the aircraft, allowing the aircraft to lift off the ground and begin liftoff.

4.Climb: After takeoff, the aircraft continues to accelerate and ascend to a set altitude. The pilot adjusts the aircraft's climb speed and angle according to the route and weather conditions.

5.Stow the landing hock cage: When the aircraft reaches a set altitude, the pilot will retract the landing gear to reduce drag and increase speed.

6.Accelerated climb: As the aircraft gets farther and farther away from the ground, the pilot will gradually accelerate and adjust the aircraft's climb speed and angle to ensure that the aircraft is safely lifted into the air and into cruising mode.

Precautions. The entire take-off process requires precise planning and operation, including the number of aircraft machinery, meteorological conditions, and the skills and experience of the pilots.

Flight principle: when the air passes through the upper surface of the wing, the flow velocity is large 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 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 faster the aircraft flies and the larger the wing area, the greater the lift generated.

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.

Airplanes fly into the sky based on the principle of fluid dynamics. When the aircraft slides, the air pressure on the upper side of the wing is less than on the lower side, which creates an upward buoyancy force on the aircraft. When the plane taxied to a certain speed, this buoyancy reached a force sufficient to make the plane fly, and the plane went into the sky.

Learn more about how airplanes fly:

Most aircraft consist of five main parts: wings, fuselage, tail, landing gear, and power plant.

The flight of an airplane has two problems to solve:

1. Rising: Rising is based on Bernoulli's principle, that is, the greater the flow velocity of the fluid (including air flow and water flow), the smaller its pressure; The smaller the flow velocity, the greater the pressure;

2. Forward: Forward depends on the forward traction generated by the power of the engine to drive the propeller rotation or the forward thrust generated by the jet.

The difference in pressure through which the air flow creates lift.

Schematic diagram of a star engine, before the advent of other more advanced aero engines, the engines of large aircraft often adopted a star design.

The star engine is a type of piston engine, which was used in airplanes as early as 1903.

Turbojet engines, abbreviated as turbojet engines, also have a long history.

In 1937, the world's first turbojet engine began to operate.

In the big picture, the turbojet engine consists of five structures.

After the air enters the engine from the intake duct, it is first compressed by the high-speed compressor, which produces high-pressure dense air to provide a large amount of oxygen, and the combustion chamber injects oil to burn, and the turbine hits the turbine backwards, and the turbine drives the compressor in front, and the gas flow is ejected from the nozzle to generate thrust.

Turbofan engines are referred to as turbofan engines.

It's easy to see the difference between a turbofan engine and a turbojet engine. A turbojet has only one air channel, technically called a "duct", while a turbofan engine has two air channels. That is, a turbojet engine is a single-ducted engine, while a turbofan is a double-ducted engine.

When the engine is running, the ratio of the air flow rate of the outer duct to the inner duct is called the bypass ratio.

The law is that the larger the bypass ratio, the more fuel-efficient, the better the economy, and the engine with a high bypass ratio has very good energy efficiency at subsonic speed, so it is widely used in passenger aircraft, transport aircraft, etc.

For engines with high bypass ratios, the main thrust does not come from the high-temperature gas sprayed backwards, but from the air sprayed backwards at high speed from the outer duct.

Modern fighters also mostly use turbofan engines, only, in pursuit of high-altitude supersonic performance, engines with low bypass ratios are used.

The reason why a ship can sail on the sea is because of the buoyancy and engine of the water, so what is it that allows an airplane to fly into the sky so heavy?