Topic How an airfoil produces lift.
Objectives The students will be able to demonstrate the principles that produces lift.
Rationale The action of the air on the wing of an airplane during flight is similar to the action of the air on a The air exerts both a upward and a downward force on the wings. This resultant force can be resolved into the horizontal drag force and the vertical lift force.
Demonstration of one principle of flight Bernoulle’s Principle. Place a small model aircraft on a float board. Blow a stream of air over the airfoil at high velocity.
Result The airflow will rise away from the board although the air stream is pushing it downwards.
Conclusions The air flowing over the upper surface of an airfoil is forced to travel farther and its velocity causes a decrease in pressure this accounts for the lift of the upper surfaces. The total lift produced by the airfoil is equal to the difference between the two pressures.
Materials
a) paper airfoil
b) flat board
c) tape
d) air hose
