How does Bernoulli’s principle apply to the flight of airplanes?

Question

If you Hold two pieces of thin paper vertically a short distance apart and blow down into the space between them, what will happen? Why?

Discuss and explain another situation where Bernoulli’s equation applies.

Thanks so much in advance!1

Answer 1

because of the rarity created by the blow between the papers the atmospheric air pressure from outside produces a whirl. the two papers may come to gether before they get a twist.

During typhoo just the reverse happens for a hut.  Inside the hut the pressure is more and outside it is less. Hence the roof of the hut is lifted and blown off.

In pest pumps also the principle applies.

the design of the airplane is in accordance with the principle of bernouli's principle.

Answer 2

Bernoulli's law predicts wing lift. The pressures on the upper and lower surfaces of a wing decrease as air velocity^2 increases. The applicable part of the equation is P1 + ρv1^2/2 = P2 + ρv2^2/2, where ρ is air density. Lift force = wing area * the difference of the pressures = A*(P1-P2) = Aρ * (v2^2-v1^2)/2. See the refs.

In the two-paper experiment, the moving air between them has a lower pressure than the ambient air outside them, so they move toward each other.