Class 11PhysicsFluid Mechanics and Surface TensionBernoulli's Theorem and Applications of Bernoulli's Theory
DifficultExplain the upward force (dynamic lift) acting on an airplane wing.
(N/A) An airfoil is a solid object with a specific shape. Due to its horizontal motion through the air,an upward force acts on it.
The cross-section of an airplane wing resembles an airfoil. The streamlines around it are shown in the figure.
When the airfoil moves against the wind,the orientation of the wing relative to the flow makes the streamlines above the wing more crowded than those below. Therefore,the speed of air above the wing is greater than the speed of flow below it.
According to Bernoulli's principle,as the speed of air increases,the pressure decreases. Consequently,the air pressure below the airfoil becomes greater than the air pressure above it.
This pressure difference results in an upward force acting on the wings,known as dynamic lift,which balances the weight of the airplane.
The cross-section of an airplane wing resembles an airfoil. The streamlines around it are shown in the figure.
When the airfoil moves against the wind,the orientation of the wing relative to the flow makes the streamlines above the wing more crowded than those below. Therefore,the speed of air above the wing is greater than the speed of flow below it.
According to Bernoulli's principle,as the speed of air increases,the pressure decreases. Consequently,the air pressure below the airfoil becomes greater than the air pressure above it.
This pressure difference results in an upward force acting on the wings,known as dynamic lift,which balances the weight of the airplane.
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