Question

write a paragraph explaining how camber and angle of attack affect the pressure, lift and drag properties of the airfoil.

Answer 1

1) Affect of Camber and angle of attack on pressure,

In general cambered wings are more efficient than flat wings. As per Burnoulli's work, the pressure of a fluid is lower when it is moving faster. Camber increases this effect and hence a camber reduces drag a force that oppose thrust. Therefore, cambered wings lift more easily than flat wings. So, camber reduces pressure over the wing.

Angle of attack is directly propotional to pressure. When we change angle of attack the pressure at every point on airfoil changes and hence center of pressure also changes which may cause airfoil to flip as it moves in the fluid.

2) Affect of camber and angle of attack on lift,

We know that, cambered wings lift easily than flat wings because camber in wings reduce the drag. In fact, a proper designed camber does require less thrust to lift. For low to medium speed we use greater camber and for high speed we reduce camber to avoid shockwaves.

Increasing angle of attack will increase the lift. In general, angle of attack is directly propotional to lift. Mathmatically,

Angle of attack = Lift × constant

If we double the angle of attack the lift doubles too.

3) Affect of camber and angle of attack on drag,

We have already discussed that camber reduces the effect of drag on wing and increases lift.

For small Angle of attack drag is nearly constant. Large angle of attack has a greater effect on drag. As the angle of attack increase the cofficient of drag also increase. Hence drag increase with angle of attack.