10/11 Flashcards
Aeroplane axis
Normal - yaw
Longitudinal - roll
Lateral - pitch
Wing taper and taper ratio
The chard from the root to the tip,
Tip chord / root chord
Aspect ratio
Wingspan 2/ spanxchord
Or wingspan2/ wing area
Wing sweep angle
Air encounters the wing at an angle. The angle between the centre of pressure line and the lateral line?
Why do we use a theoretical rectangular wing
Simplified and has similar aerodynamic properties
The wing is put in at an angle at the wing root, what is called
Rigging angle
What is the angle of incidence,
The angle between the chord line and the aircraft’s longitudinal axis
What is the washout
Reducing the angle coincidence towards the wing tip
Dihedral, anhedral
Dihedral, when the wing tip is higher than the root, common in low wing aircraft
What is Span wise flow influenced by
The inertia of the air mass flow, local pressure differences around the aircraft
How does a wing tip vortex come about
Airflows from high to low pressure, high: underneath, low-top,
high pressure difference-larger vortices
Factors affecting the strength of tip vortices
Lift. - the pressure differential between upper and lower surfaces -tip vortices can only exist when the wing is producing I lift
Airspeed - molecules have a higher chance colliding with lower speeds = tip vortices will occur.
Aspectrato - low = intense vertices = the width is larger = more time available to influence movement of the airflow
Effect of tip vortices on down wash
Each vortex rotates sharply downwards behind the trailing edge
Due t viscosity, it drags the surrounding air down with it = small downward velocity component l the air
Effect of tip vortices on drag
Vortices contain a large amount of rotational energy
This energy comes from the aircraft
Extra energy provided t the vortices is feltasdrag
Wake turbulence
300ft/sec
Greatest area of risk is behind the aircraft, within 1000 ft of its altitude, can extend several miles behind
Greatest at low speed and high angle G attack
