8 Flashcards
4 fundamentals in aerodynamics?
Mass, Length, Time and Temperature
Symbol for speed?
V
Formula for speed?
Speed = Distance / Time
Symbol for acceleration?
a
Formula for acceleration?
Acceleration = Change in velocity/Time taken
Symbol for acceleration due to gravity?
G
What is the average acceleration due to gravity?
9.8ms*2
What is acceleration measured in?
Metres per square second
Calculation for weight?
Weight = Mass x Acceleration due to gravity
Calculation for work?
Work = Force x Distance
What is Work measured in?
Newton metres or Joules
Calculation for Force?
Force = Mass x Acceleration
What is Force measured in?
Newton’s
What is the measurement for Power?
Watts/Newton metres per second
Calculation for Power?
Power = Force x Distance
———————
Time
What is the unit for work?
Joules (J)
What is the symbol for static pressure?
p
What is the formula for pressure?
Pressure = Force/Area
What is static pressure?
Static pressure acts equally in all directions
What is dynamic pressure?
Dynamic pressure acts only in the direction of flow
What is the symbol for dynamic pressure?
q
What is the symbol for the speed of sound?
a
What is the formula to calculate the speed of sound?
Speed of sound = 20 x (sq. root of T(Kelvin))
What is the constant used in the formula for the speed of sound?
20
What is a diffuser outlet?
When diameter increases and speed decreases
What is a jet outlet?
Diameter decreases and speed increases
What is Bernoulli’s principle?
Total pressure is always the sum of static pressure and dynamic pressure. The total pressure remains constant.
What is the point of stagnation?
The speed of the airflow falls to zero and the static pressure equals the total pressure.
Where is up-wash experienced?
At the leading edge of the wing
Where is down-wash experienced?
At the trailing edge of the wing
What is the Magnus Effect?
A rotational cylinder creates an increased local speed on the top and decreased on the bottom
How do vortices form?
They form in pairs, rotating counter clockwise
What is a profile?
A cross-sectional area of a wing
What can a wing and profile section also be called?
Aerofoil and Aerofoil Section
What is the camber?
The camber of the profile is the displacement of the mean camber line from the chord line.
What camber would you find on a typical low speed profile aerofoil?
A minimum camber at 5% located 45% aft of the leading edge
What is the Fineness Ratio?
The maximum thickness of a profile defined as a fraction
What thickness would you find on a typical low speed profile?
A typical low speed profile might have a maximum thickness of 18% located 30% aft of the leading edge.
What is the Angle of Attack?
Symbol is alpha - The angle between the chord line and the relative wind
What is the Angle of Incidence?
Symbol is Gamma - the angle between the chord line and the longitudinal axis of the aircraft
How do you calculate wing area?
Wing span x Wing chord
What is the symbol for the Taper Ratio?
Lambda
What is the Taper Ratio?
It is the ratio between the tip chord and the root chord (Ct/Cr)
What is the aspect ratio?
The wing span divided by the average chord
What is the sweep angle?
The sweep angle is the angle between the line of 25% chords and a line perpendicular to the root chord.
Which direction does a positive sweep go?
Backwards
What is the dihedral angle?
When the wing tip is either above or below the horizontal plane
