Lift generation Parafoil

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What is parafoil?
A leading edge opened aerofoil is called as “Parafoil”. We know already that leading edge is facing into the wind for aerofoil. Since it has been opened, it just admits the air to flow inside the volume covered by the upper and lower surfaces.

How aerofoil creates lift?
What is bernouli's principle? How it suits to the aerofoil?

Aerofoil has its upper surface curved, whereas bottom is moreover flat. Physically the curved portion accelerates the flow and so the top side airflow is getting increase in velocity. Lower surface is experiencing less velocity when comparing the upper surface.


We know from Bernoulis law that for a fluid flow, if fluid velocity increases then pressure drops. In the upper we are feeling less pressure and in the bottom a high one.

Bernoulis principle:
Total energy of a steady flowing fluid system is constant.
ƩE= k
PE+KE= k
mgh+0.5 mv2 =k
dividing both sides by volume
ρgh+ 0.5ρv2=k



High pressure pushes the object to compensate the low pressure zone created above; because of it body feels an upward force called as Lift.

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