M8 Revistion Flashcards
Equation for Acceleration
Velocity change / time taken
Gravitational acceleration speed
9.8 meters per square second
Equation for force
Mass * Acceleration
Equation for weight
Mass * gravity
Equation for work done
Force * Distance
Equation for power
Force * Distance
/time
What is Pressure
The force acting on a unit of area.
Equation for static pressure
Height * Density * Gravity
Equation for Dynamic Pressure
Density * 0.5 * Speed^2
Equation for Pressure
Force / Area
How does speed of sound relate to temperature
The speed of sound is lower at lower temps and higher at higher temps.
Equation for Mach Number
Speed of Aircraft / Speed of Sound
What is Subsonic
Aircraft speed is below the speed of sound
What is Transonic
The aircraft speed is at the speed of sound
What is supersonic
Aircraft speed above the speed of sound
What is troposphere
The lowest layer where weather forms
What is staposhere
The heights level where there no weather and the temp stays the same
Tropopause
The boundary between the staposhere and the troposphere
What does I.S.A. stand for
International Standard Atmosphere
What are the ISA’s
288K
1.225 ks/m^2
-6.5K/1000m
1013.25Hpa
When is air Incompressible
When flight is in the subsonic region
Continuity equation states
The speed of the airflow is inversely proportional to the area of the cross section
What is a diffuser outlet
When the diameter increases and the speed decreases
What is a jet outlet
When the diameter decreases and the speed increases
Equation for Totle Pressure
Static pressure + dynamic pressure
When is Bernoullis principle used
To measure airspeed
What is Magnus effect
When the pressure on the top of the wing is equal to the bottom of the wing.
What is profile
The cross section of the wing
What is the chord line
A straight line connecting the leading edge to the trailing edge
What is the mean camber line
A line drawn between the upper and lower surfaces of the profile
What is camber
The displacement of the mean camber line from the chord line
What i# fineness ratio
The fraction which determines the thickness of the wing profile
What is flight path velocity
The speed of the aircraft in a curtain direction through the air
What is relative wind
The speed and direction of the air acting on the aircraft
What is Angle of attake
The angle between the chord line and the relative wind
What is positive sweep
Wings pointing backwards
What is negative sweep
Wings pointing forwards
What is dihedral angle
Wings pointing up
(Positive dihedral)
What is Anhedral Angle
Wing pointing down
(Negative Dihedral)
What are the 2 components of aerodynamic forces
Lift and Drag
Equation for theoretical lift
1/2 * p * v^2 * a
Equation for coefficient of lift
Measured lift / theoretical lift
Benefit of a thick profile wing
It can fly at slower speeds as it has a lower stall speed
Disadvantage of a thick profile wing
Produces more drag and has a lower Mach Number
What is centre of pressure
The point where all forces and pressures act
Lift and drag depend on:
Surface area of profile
Dynamic pressure
Shape of profile
Edge of attack
What are the effects of ice on the wing
Reduces the maximum coefficient and maximum angle of attack
What is a polar diagram
Shows how lift and drag coefficients can be combined
What is induced drag
Drag on the wing caused by lift
What is parasite drag
Drag caused by aerodynamic interference
What is compressible drag
Drag caused by a shockwave of an aircraft approaching the speed of sound
What is the purpose of wingtips
To reduce induced drag
What is form drag
When the pressure in front is different to the pressure behind.
How to reduce form drag
By streamlining the aircraft
E.g. retracting the landing gear
What is interference drag
The turbulence In the airflow caused by the sharp corners of components joined together
How can interference drag be reduced
Use of fairings
What are the 4 types of wing
Elliptical wing
Rectangular wing
Tapered wing
Swept wing
What is aerodynamic centre
A point on the chord line where the magnitude of the pitching moment doesn’t change
What is centre of lift
When the CL is in font of the C.G. the nose is pitched up and when the CL is behind the C.G. nose is pitched down
What is the mean aerodynamic chord
The average chord length of a wing
What is stall
When the angle of attack increases beyond a curtain point that lift begins to decrease.
What are the 3 types of stall
Deep stall
Wing root stall
Wing tip stall