WING SHAPE AND ITS EFFECT ON LIFT

WING SHAPE AND ITS EFFECT ON LIFT

The total Lift generated by an aircraft wing depends on three factors

1. Degree of Induced Downwash( Caused by wing tip vortices)

2. Chord wise Pressure Distribution

3. Plan form Shape of the wing

Since the aircraft wing is similar on both sides it is appropriate to consider only the semi span of the wing to study about the effect of lift on wing shape.

Let us consider three types of wings and its lifting ability, which depends on the angle of attack also.

1. Rectangular

2. Elliptical

3. Tapered

The above figure illustrates the picture of how effective angle of attack varies with distance from aircrafts centre line.

In case of rectangular wing the effective angle of attack

Remains Constant - First 50 % of the semi span

Quickly reduces to zero degrees - Next 50% of the semi span

In case of Tapered wing the effective angle of attack

Increases – First 70% of the semi span

Reduces to Zero – Next 30% of semi span

The above results indicate that the Chord length of the wing affects the size of wing tip vortex. The rectangular wing produces a greater wing tip vortex than the tapered wing because a wider tip chord allows more air to flow towards the upper surface of the wing, which intensifies the vortex size.

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