M8 Aerodynamics Flashcards
Disadvantages of swept wings
Reduces lift, swept wings need to be longer, has to be heavier
How’s lift created
Created as velocity of air is taken over the wing and therefore the static pressure above the wing decreases when the static pressure below stays the same so there for the pressure below is higher than above which causes lift to occur
What’s the Magnus affect
When an cylinder rotates which then increases the speed on the upper surface which then cause# lift due to the static pressure now being lower on top
What’s the mean camber line
The curved line that sits halfway between the upper and lower surface
What factors affect lift
Icy conditions
Angle of attack
Thickness of profile
Camber line
Earths average atmospheric pressure ?
14.7 psi or 1013Hpa
How do you calculate wing area
Wingspan x chord
How do you calculate Mach number
Speed of aircraft divided by speed of sound
What’s centre of pressure
The centre point from where all pressure/force is said to act from
Factors that affect drag
Angle of attack and if the aircraft is at a climb
What’s the stratosphere
The point from where temperature no longer changes and there are no more clouds
What’s the difference between positive and negative sweep wings
Positive wings are facing backwards whereas negative wings are facing forwards
Advantages of swept wings
Provides stability
Good for aircraft that want to fly at speeds close to speed of light or over
How does altitude affect the speed of sound
The higher the altitude the slower the speed of sound because as the altitude gets greater the temperature decreases which slows down the speed of sound
What’s the difference between subsonic, transonic and supersonic
Subsonic is travelling at speeds up to critical Mach
Transonic is the speed of the aircraft that’s travelling at the speed of sound
Supersonic is the speed of the aircraft that’s exceeding the speed of sound
What’s critical Mach
Critical Mach is the speed an aircraft can travel at without any parts of the plane exceeding the speed of sound
Average world temp in Kelvin
288k
Average air density
1.224 kg/m cubed
What’s the formula for theoretical lift
P divided by 2 x v squared x a
What’s the angle of incidence
Angle between cord line and longitudinal axis of aircraft
What’s the angle of attack
The angle between the chord line and the relative wind
How do you work out dynamic pressure
One half x density x speed squared
How do you work out Static pressure
Density x height x gravity
Difference between a anhedral and dihedral
Dihedral is when the wing tips are higher than the wing base
Anhedral is when the wing base is higher than the wing tips
What’s air called that’s taken up from the leading edge? What’s air called that’s discharged from trailing edge?
Upwash
Downwash
What’s a cord line
The line that goes from the leading edge to the trailing edge
What’s fineness ratio
The maximum thickness of a profile expressed as a ratio or a percentage
What’s relative wind
The speed and direction of the air acting on an aircraft which it’s passing through
What are the two components of aerodynamic forces
Drag and lift
What part of atmosphere does weather occur in
Troposphere
How far up is the stratosphere from sea level
11km
How much does temperature drop by as you go up a km
6.5
What happens to static pressure as dynamic increases
Static pressure must decrease and vice versa
What’s the stagnation point
The point where velocity of airflow is 0
What type of wave is a sound wave
Longitudinal
