AER1 Flashcards
To be kings and queens of aero (28 cards)
Major Structural Components of Aircraft
Wings Tail Fuselage Engine Undercarriage Flight Control Surfaces
Describe the physical forces acting upon an aircraft in flight
Static Forces: Weight, atmospheric air pressure
Dynamic Forces: Thrust, Lift, Drag, dynamic air resistance
Describe the three axes of aircraft movement, their stabillity and motion.
Lateral - Longitudinal stability - Pitch
Longitudinal - Lateral stability - Roll
Normal - Directional Stability - Yaw
Primary and Secondary Effects of: Elevator
Primary: Create Pitch for Longitudinal Control
Secondary: Change angle of attack and flight path which changes altitude and speed
Primary and Secondary effects of: Rudders
Primary: Create Yaw for directional control
Secondary: Roll, as the outer wing has a faster airspeed thus creating more lift than the inner wing
Primary and Secondary effects of: Ailerons
Primary: Create Roll for lateral control
Secondary:
Adverse aileron yaw due to the increased drag that is created from the wing with increased lift (aileron down).
Yaw in the direction opposite to roll direction
Describe Air Pressure
Static Pressure: result of air pushing down as a result of gravity
Dynamic Pressure: result of motion through air and varies with density
Describe Air Density
Is affected primarily by temperature and pressure.
Humidity: air that contains water vapour is less dense than dry air at the-same temperature.
Describe Bernoulli’s Theorem
The Theorem states that air moving over the curved upper surface of the wing will travel faster and thus produce less pressure than the slower air moving across the flatter underside of the wing
What is the Chord Line
Straight line connecting Leading Edge and Trailing Edge
What is the Chord Length
Length if Chord line
What us the Mean Aerodynamic Chord
A percentage of the wing span where the average distance from LE to TE is located
What is Camber
The distance from the Mean Camber Line to the Chord Line and may vary.
Wings with greater Camber produces more lift but also more drag.
What is the Mean Chamber Line
The Line that runs across the aerofoil that is equidistant from the upper and lower surfaces
Describe Continuity
Conservation of Mass: mass of fluid cannot be created or destroyed there must move through different sized tubes at thesame rate
Why don’t we just use a flat plate? Instead of an aerofoil?
Flat plates will generate total reaction force(lift) at correct suitable of attack. But at larger angles will cause airflow to separate creating in vortices.
Aerofoil produces the least drag.
Describe Relative Airflow
Relative direction and speed if air BEFORE it is influenced by the aircraft.
Is always equal and opposite direction of the flight path.
What is the Angle of Attack
The angle between the Chordline and RAF
Difference between Angle of Incidence and Angle of Attack?
Angle of Incidence: angle that the wing is fixed on the longitudinal axis of the plane.
AoA: angle between chord line and relative air fow
Forces in Flight: Straight and Level
Opposing forces equal. Constant Altitude and Velocity.
Forces in Flight: Steady Climb
Forces in equilibrium (unchanging but also unequal)
Lift = component of weight perpendicular to flight path
Lift < Total Weight(always points down)
Lift reduced
Thrust = Drag + Component of Weight acting rearwards
thus, Thrust > Drag
Thrust increases
Forces in Flight: Steady Descent
Forces in equilibrium (unchanging airspeed)
Lift = component of weight perpendicular to flight path
Lift < Total Weight
Lift reduced
Component of weight forward along flight path will increase speed until thrust reduces
Thrust Reduced
What does increasing Angle of Attack do?
Increases curvature of aerofoil
Increases airflow acceleration above and resultant pressure drop
Increase lift
Increase drag (greater surface area facing forward)
How to maintain steady flight with changing weight?
Increase in weight,
Will have to increase lift force by:
Increasing Airspeed
Increasing AoA
