M8 Flashcards

1
Q

How is static pressure denoted?

A

Letter P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is Dynamic pressure denoted?

A

Letter q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What direction does static pressures travel in?

A

All directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What direction does dynamic pressure travel in?

A

Direction of flow?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the temperature at sea level?

A

15 degrees 288 Kelvin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is speed of sound denoted?

A

Letter a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the density at sea level?

A

1.225 kg/m cubed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the equation for speed of sound?

A

A = 20 square root of temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the pressure at sea level?

A

1013.25

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the subsonic region?

A

Travelling below the speed of sound and the region up until Mcrit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where will the pressure waves be when travelling in the subsonic region?

A

Around the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the transonic region?

A

Region between Mcrit and up to Mach 1.3. Will be travelling at the speed of sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are the pressure waves when travelling in the transonic region?

A

Shockwave starts to form as pressure wave cannot escape the front of the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Mcrit?

A

The maximum speed at which an aircraft can travel before forming a shockwave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the supersonic region

A

Travelling faster then the speed of sound, Mach number is larger then 1.3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where are the pressure waves when travelling in the supersonic region?

A

Behind the aircraft?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the equation for dynamic pressure?

A

q = 0.5 x Rho x V squared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a property of air in the subsonic region?

A

Incompressible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does a jet outlet work

A

Diameter decreases and speed increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does the diffuser outlet work?

A

Diameter increases and speed decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the stagnation point?

A

Point on the leading edge where dynamic pressure is = 0 and static pressure is = total pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Explain the continuity equation

A

Speed of airflow is inversely proportional to cross sectional area of the tube as long as the diameter remains constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do you work out the Mach number?

A

Speed of aircraft / speed of sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is up wash?

A

Streamlines pass the upper surface of the aerofoil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is down wash?

A

Streamlines on the upper surface on the trailing edge flow downwards of the aerofoil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the Magnus effect?

A

Cylindrical rotation which causes an increase of local speed above the win and a decrease of local speed below the wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a general rule about vortices?

A

They always form in pairs and rotate anti clockwise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where is the max camber of a low speed profile found?

A

5% of chord line and 45% aft of leading edge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where is the max thickness of a low speed profile found?

A

18% of chord line and 30% aft of leading edge?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do you determine the angle of incidence?

A

Chord line of profile and longitudinal axis of the aircraft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is the angle of incidence denoted?

A

Gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How is the angle of attack determined?

A

Angle between the chord and the direction of wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do you work out wing area?

A

Wing span x average chord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How is taper ratio found?

A

CR / CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is aspect ratio?

A

Wing span / average chord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What type of a/c has a high aspect ratio?

A

Gliders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What type of a/c have a low aspect ratio?

A

Fighter jets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

If there is a higher aspect ratio then what is there less off?

A

Induced drag

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Which direction do positive sweep wings go?

A

Backwards

40
Q

Which direction do negative sweep wings go?

A

Forwards

41
Q

If the wing is more swept back then what ca this achieve?

A

Higher lateral stability

42
Q

What are dihedral angled wings?

A

Wings that angle upwards

43
Q

What do dihedral wings achieve?

A

More lateral stability

44
Q

What are anhedral wings?

A

Wings which are angled downwards

45
Q

What benefits do anhedral wings have?

A

Increases roll performance and monouverability

46
Q

What 4 factors does lift and drag depend on?

A

q
Surface area
Shape of profile
Angle of attack

47
Q

What is the equation for theoretical lift?

A

1/2 x Rho x V^2 x Surface area

48
Q

What is lift in comparison to the relative wind?

A

Perpendicular

49
Q

What is drag in comparison to the relative wind?

A

Parallel

50
Q

How do you work out the Cl of lift?

A

Measured lift / theoretical lift

51
Q

What is the total lift equation?

A

1/2 x Rho x V^2 x S x Cl

52
Q

What is alpha max?

A

Th maximum angle of attack which can be achieved before a stall occurs

53
Q

What can ice on the profile surface do?

A

Reduce the maximum Cl

Reduce the maximum angle of attack

54
Q

What is the polar diagram?

A

Determines the best angle of attack for each aircraft by combining the lift and drag coefficients for each angle of attack and using a tangent line to determine which one is best

55
Q

Higher glide ratio = ?

A

Lower induced drag

56
Q

What are the 3 types of drag?

A

Induced
Parasite
Compressible

57
Q

What is the cause of induced drag?

A

Lift

58
Q

What are the 3 types of parasitic drag?

A

Form
Friction
Interference

59
Q

What does form drag involve?

A

The distribution of pressure

60
Q

What does friction drag involve?

A

Air particles getting trapped on skin

61
Q

What does interference drag involve?

A

Sharp edges

62
Q

How do you reduce friction drag?

A

Smoother skin

63
Q

How do you reduce interference drag?

A

Using fairings

64
Q

If the form drag is high then what will the friction drag be?

A

Low

65
Q

Where is the laminar boundary found?

A

From the leading edge to the maximum thickness

66
Q

Do the air particles move from layer to layer in the laminar boundary?

A

No

67
Q

Where is the turbulent boundary found?

A

Downstream of the laminar boundary

68
Q

When laminar flow breaks down what does this result in?

A

Turbulent flow

69
Q

Is the turbulent boundary thicker or thinner then the laminar boundary?

A

Thicker

70
Q

What is total drag?

A

Induced drag + parasite drag

71
Q

If speed increases what does parasitic drag do?

A

Increase

72
Q

At lower speeds will the total drag be higher or lower?

A

Higher

73
Q

What are the four forces acting on an a/c during flight?

A

Lift
Thrust
Weight
Drag

74
Q

What must be equal during horizontal flight in relation to the forces?

A
Lift = weight
Thrust = drag
75
Q

How do you work out the glide ratio?

A

Forwards velocity / downwards velocity

76
Q

How do you work out the load factor?

A

Lift in turn / weight

77
Q

What do flaps do?

A

Increase camber at the trailing edge to extend the alpha max

78
Q

What are the 4 types of flaps?

A

Plain
Slotted
Split
Fowler

79
Q

What is a fowler flap?

A

Travels rearwards and downwards increasing the wing area as well as the camber. Can increase Cl by up to 90%

80
Q

What is a plain flap?

A

Basic form of trailing edge flap. Abrupt change in camber can cause airflow to break away from wing

81
Q

What is a split flap?

A

More efficient then a plain flap. Airflow is less likely to break away from wing.

82
Q

What is a slotted flap?

A

Forms a slot as the flap is lowered. This re energises the airflow

83
Q

What is positive static stability?

A

Object has a tendency to return to equilibrium

84
Q

what is Negative static stability?

A

Objects continue to travel in displacement direction

85
Q

What is neutral static stability?

A

Equilibrium encountered at any point of displacement

86
Q

What is positive dynamic stability?

A

Damped oscillation, starts large and gets smaller

87
Q

What is neutral dynamic stability?

A

Undamped oscillations, remains constant

88
Q

What is negative dynamic stability?

A

Divergent oscillation, starts large gets larger

89
Q

What are the 3 different axis an a/c uses?

A

Longitudinal
Vertical
Lateral

90
Q

What are the 3 types of stability that act on an a/c?

A

Lateral
Longitudinal
Directional

91
Q

What axis does roll happen around?

A

Lateral

92
Q

What axis does pitch happen around?

A

Longitudinal

93
Q

What axis does yaw happen around?

A

Vertical

94
Q

What is another name for directional stability?

A

Weathercock

95
Q

How do you increase directional stability?

A

Dorsal fin
Keel surface
Sweep back of wing

96
Q

What is lateral stability determined by?

A

Wing
Angle of attack
Dihedral angle
Sweep back angle