Basic Aerody Flashcards

(81 cards)

1
Q

What is kinetic energy?

A

Energy an object possesses due to its speed

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

What is potential energy?

A

Energy an object possesses due to its height.

Gravitational potential energy

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

In a loop, when will an aircraft have its maximum kinetic energy?

A

Before entering and just after exiting

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

In a loop, when will an aircraft have its maximum potential energy?

A

At the top of the loop

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

What are the two types of pressure?

A

Static Pressure (Ps) and Dynamic Pressure (Pd)

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

What is static pressure?

A

The pressure caused by gravity pulling air molecules down toward the centre of the Earth

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

What happens to static pressure as altitude increases?

A

Decreases - due to air being less dense at higher altitudes

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

How does pressure move?

A

High to low

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

What is dynamic pressure?

A

Kinetic energy to motion

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

What is the formula for dynamic pressure?

A

Pd = 1/2 rho v^2

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

What is Bernoulli’s Theorem?

A

Total pressure does not change.

I.e. Pt = Pd + Ps

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

What is the Coanda effect?

A

The tendency of the airflow to follow a surface with gentle curvature rather than continue its original path until the stalling angle is reached

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

What does the air do as a result of the Coanda effect?

A

Results in the air being deflected downward after it leaves the trailing edge of the wing

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

What is an aerofoil?

A

Any surface which is designed to provide an aerodynamic force when interacting with a moving stream of air

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

What is the chordline of an aerofoil?

A

The straight line joining the leading edge to the trailing edge

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

What is the mean camber line of an aerofoil?

A

The line drawn an equal distance from the upper and lower surfaces

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

What is the thickness of an aerofoil?

A

The distance between the upper and lower surfaces

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

What is the camber of an aerofoil?

A

The curvature of an aerofoil

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

What is a well-cambered aerofoil used for?

A

Typical high-lift, low speed wing

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

What is a symmetrical aerofoil used for?

A

Typical horizontal stabiliser

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

What is aspect ratio?

A

It is span divided by chord

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

What does a wing with high aspect ratio bring?

A

Can reduce induced drag

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

What is Relative Airflow (RAF)?

A

Airflow in the opposite to the direction of the path of the aircraft

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

What is angle of attack (AoA)?

A

The angle between the chordline and relative airflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the centre of pressure (CoP)?
A point on the top surface of an aerofoil which the total reaction of all lifting aerodynamic forces is said to act
26
Where is the high pressure around an aerofoil?
Underneath
27
Where is the low pressure around an aerofoil?
On top
28
What is the effect of flap?
Causes a greater increase in drag than lift
29
What is induced drag?
Drag created when creating lift
30
What is the equation of lift?
L = C(L) 1/2 rho v^2 S
31
What is C(L) in the equation of lift?
Coefficient of lift, made up of AoA and Wing Shape
32
What is S in the equation of lift?
Surface area
33
How can we increase C(L)?
Increase AoA Increase camber Deploy flap Increase thickness/chord ratio
34
What is the thickness/chord ratio?
Is an aerofoils relative thickness
35
What are the two types of drag?
Induced drag and Parasite drag
36
What is parasite drag made up of?
Skin friction Interference drag Form drag
37
What is skin friction?
Exists between an object and the air in which it is moving through
38
What is interference drag?
Air mixing at junctions creates turbulence in the region of the joint
39
How is interference drag reduced?
With the use of fairings
40
What is form drag?
Results from airflow separation
41
How is form drag reduced?
Reduced by using streamlined parts
42
Which fineness ratio produces the least drag?
Large fineness ratio
43
What happens to parasite drag as airspeed increases?
Parasite drag increases
44
What happens to induced drag as AoA increases?
Induced drag increases
45
When causes induced drag to be greater?
The greater the pressure difference between the bottom and top surface, the greater the induced drag
46
Why does a slower aircraft produce more induced drag?
The slower the aircraft flies, the more time air has to spill over the wing tip
47
Where is induced drag produced?
At the wingtip as air spills over from high to low pressure
48
What increases the pressure difference over an aerofoil?
Aircraft weight AoA Aspect ratio
49
What happens to induced drag as airspeed increases?
Induced drag reduces
50
What is total drag?
Total Drag = Parasite Drag + Induced Drag
51
What point is the min drag point?
The best glide speed
52
What is the drag equation?
D = C(d) 1/2 rho v^2 S
53
What is C(d) in the drag equation?
The coefficient of drag
54
What impacts on the C(d)?
The AoA and wing shape
55
What is wake turbulence?
A result of air spilling around the wingtip due to the high pressure below the aerofoil and lower pressure above
56
What happens to wake turbulence as AoA increases?
Wake turbulence increases
57
What happens to wake turbulence as IAS decreases?
Wake turbulence increases
58
What happens to wake turbulence as weight increases?
Wake turbulence increases
59
What happens to wake turbulence as aspect ratio increases?
Wake turbulence decreases
60
What happens to wake turbulence if you increase the dissipating time?
Wake turbulence decreases
61
When are wingtip vortices at their greatest strength?
When an aircraft is heavy, slow with gear and flaps up
62
When is wake turbulence strongest?
Just prior to take-off
63
Where should you fly to avoid wake turbulence?
Upwind and above
64
When taking off after a large aircraft takes off, where should you aim to rotate?
Aim to lift off well before the larger aircraft's rotation point and climb above their flightpath
65
When taking off after a large aircraft has landed, where should you aim to rotate?
Aim to lift off well after its touchdown point or wait for it to dissapte
66
When landing after a large aircraft lands, where should you approach and aim to land?
Approach above it's flight path and aim to land well beyond it's touchdown point
67
When landing after a large aircraft takes off, where should you aim to touchdown?
Aim to touchdown well before its point of rotation
68
Where should you aim to land when a large aircraft lands on a crossing runway?
Plan to cross above the larger aircraft's flightpath and touchdown well beyond the runway it has landed on
69
Where should you aim to land when a large aircraft takes-off on a crossing runway? (Consider both pre/post intersection departure)
If the rotation is beyond the intersection then land before the intersection. If the rotation is before the intersection, then go around unless the landing can be completed before the intersection
70
How fast does wake turbulence sink?
400-500 fpm
71
How far does wake turbulence extend?
2 wingspans horizontally and 1 wingspan vertically
72
How do you avoid wake turbulence en-route?
Aim to fly 200ft above or 1000ft below
73
How long can vortices persist for at altitude and on the ground?
5 mins at altitude | 3 mins on the ground
74
If a heavy aircraft conducts a go around, what should you do?
Assume the entire runway could be a hazard and delay or discontinue the approach
75
Do helicopters produce wake turbulence?
Yes, known as rotor downwash
76
When is a helicopters wake turbulence greatest?
When a helicopter is operating at lower speeds
77
How far can helicopter wake turbulence be hazardous for?
Up to a radius of approximately 3x rotor diameter
78
What is equilibrium?
Forces acting on an object are in balance and there is no acceleration
79
What is a moment?
Force x Arm
80
What is inward spanwise drift?
Air on the top of the wing moves inwards
81
What is outward spanwise drift?
Air on the bottom of the wing move outwards