principles of flight ( chapter 4 > required knowledge and skills )

The angle of attack is the angle between

The aerofoil CHORD LINE and the DIRECTION OF THE AIRFLOW

Centre of pressure

Is the average point which the aerodynamic forces act

Drag

1. Is the component of the total reaction

2. Parallel to the free stream flow

Lift

1. Is the component of total reaction

2. Perpendicular to the free stream flow

The chord line

Is a imaginary straight line draw between the centre of the leading edge and the trailing edge

Thickness to chord ratio

Is the ratio of the aerofoil maximum thickness

The point of maximum thickness of an aerofoil occurs at

The first 1/3 of the chord length

The mean camber line

Is an imaginary line half way between the upper and lower surfaces

Camber

Describes the distance between the mean camber line and the chord line

What is the upwards air before the leading edge

Up wash

The downward air leaving the training edge is called

Trailing edge

What is the velocity of the air at the stagnation points

Zero

Above the aerofoil the velocity is …

Velocity increases