Aerodynamics Flashcards
1
Q
What are the 4 Forces of Flight?
A
- Lift
- Weight
- Thrust
- Drag
2
Q
How is Lift generated?
A
- It is generated by the wings
3
Q
What are the Theories of Lift?
A
- Pressure Difference
- Newton’s Third Law
4
Q
What is Pressure Difference?
A
- The upper surface of the wing is curved while the lower surface is relatively flat. The air flowing over the top camber increases in speed, decreasing pressure. The air flowing beneath the wing slows down, increasing pressure. The high pressure wants to move to the area of low pressure which pushes up on the wing
5
Q
How does Newton’s Third Law apply to the wings generating lift?
A
- The wing’s downward push results in an equal and opposite push back upward
6
Q
What is Bernoulli’s Principle?
A
- As the speed of a fluid increases, its pressure will decrease and vice versa
7
Q
How is Thrust generated?
A
- It is generated by the propeller
8
Q
How does the Propeller generate thrust?
A
- The propeller is a rotating airfoil so it essentially produces thrust the same way wings produce lift
- The propeller is twisted so it can produce equal thrust from the hub to the tip
9
Q
How is Weight generated?
A
- It is generated by gravity
10
Q
How is Drag generated?
A
- It is generated by the aircraft moving through air
11
Q
What are the Types of Drag?
A
- Parasite Drag
- Induced Drag
12
Q
What is Parasite Drag?
A
- It is drag caused by the aircraft’s structure and material as it moves through air
- It consists of skin friction, form, and interference drag
13
Q
What is Skin Friction drag?
A
- It is caused by the aerodynamic resistance due to the contact of moving air on the surface of the aircraft
14
Q
What is Form drag?
A
- It is the result of the aerodynamic resistance to the shape of the aircraft
15
Q
What is Interference drag?
A
- It is the drag that is generated by the mixing of airflow streamlines between airframe components
16
Q
What is Induced Drag?
A
- It is caused by generating lift
- As the high and low pressure air flow off the wingtip, they try to mix resulting in wingtip vorticies. These vorticies create a downwash behind the trailing edge of the wing. This downwash is as if someone is pulling on the back of the aircraft
- It becomes larger as AOA or lift increases