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Flashcards in Air flow Deck (15)
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1
Q

What does the term laminar flow mean

A

air flows smoothly in a streamlined manner

2
Q

What does the term turbulent flow mean

A

Air molecules travel in random motion which is superimposed on the overall flow direction

3
Q

What does the term flow separation mean

A

separated air flow which is not moving in the direction of general air flow

4
Q

Where on the CL v Angle of attack graph does it show where air separation begins

A

Where graph has stop being linear an tapers off

5
Q

What is Cl limited by during take-off and landing

A

Stall

6
Q

How does an increase in camber effect Cl

A

Cl increases

7
Q

What causes shockwaves

A

Before getting to the wing, air is undisturbed. However when it hits the wing there are abrupt changes in it’s speed, temperature and pressure which lead to shockwaves

8
Q

What causes a sonic boom

A

Due to a sudden change in pressure. “vapour cone” is due to change in temperature as air condenses slightly, you can see it clearly

9
Q

What is the speed of sound in m/s

A

340m/s

10
Q

Calculating Mach number

A

airspeed/speed of sound

11
Q

What type of flow is it when M

A

Subsonic flow:

air flow behaves normally

12
Q

What Mach number region is subsonic flow

A

M

13
Q

What type of flow is it when 0.7

A

Transonic flow:
Compressibility becomes important, same locally supersonic flow
Bernoulli’s equation breaks down

14
Q

What Mach number region is transonic flow

A

0.7

15
Q

What type of flow is it when M > 5

A

Hypersonic flow:
Heat becomes a massive issue!
Only relevant to rockets