Usually, a passenger aircraft weighs tens or even hundreds of tons, the world's largest civil aviation aircraft Airbus A380, the aircraft itself has a maximum take-off weight of 575 tons, so as a behemoth, it is not an easy task for the aircraft to carry out controlled continuous power flight at high altitude.
So how the aircraft is flying in the sky, balloons, airships and other aircraft can fly in the sky, is the use of hydrogen or helium with a density smaller than the air, to provide lift to achieve high-altitude flight, the density of the aircraft is much greater than the air, the lift it takes off comes from the power generated by the movement of the wing in the air, from the cross section of the wing, it can be seen that its upper curve and the lower curve are not symmetrical, and when observing the circulation distribution around the wing when the aircraft is flying, it will be found that the streamline above the wing is densely flowing, and the streamline thinning velocity below is small.
According to Bernoulli's equation, it can be obtained that the pressure above the wing is small and the pressure below is strong, so the pressure difference between the two is the main source of lift in the aircraft. For example, if you blow two pieces of paper close to the middle, you will find that the pieces of paper are tightly attached together, because the gas in the middle of the paper is blown by us to accelerate the flow rate and the pressure is reduced, and the air pressure outside the paper will squeeze the paper pieces together without changing.
In addition, the operation principle of the wing is also related to the Kangda effect, we open the faucet to let the water flow gently fall, the back of the spoon slowly close to the water flow, you will find that the water flow changes the flow trajectory and begins to fall along the surface of the spoon, while the spoon has a pointing attraction to the bulge This is the Kangda effect.
Similarly, the bulge of the wings of an aircraft can cause a large amount of airflow to deflect downwards to produce an upward lift, but today's jets take advantage of more than just these principles, they mainly rely on the backward injection of high temperature gas to achieve flight