High Speed

Question 1

What is the term used for the speed of sound?

Answer 1

Mach 1

Question 2

What does the speed of sound vary with?

Answer 2

Temperature

Question 3

How do you calculate Mach no. ?

Answer 3

Velocity of object(v)/local speed of sound(a)
M=v/a

Question 4

What is the subsonic speed range?

Answer 4

0-0.8 Mach

Question 5

What is the transonic speed range?

Answer 5

0.8-1.2 Mach

Question 6

What is the transonic speed range?

Answer 6

0.8-1.2 Mach

Question 7

What is the supersonic speed range?

Answer 7

1.2-5 Mach

Question 8

What flow is measured for speed ranges?

Answer 8

Compressible flow

Question 9

Where is subsonic flight used?

Answer 9

For most commercial and general aviation flights

Question 10

Is air compressible or incompressible in subsonic flight?

Answer 10

Incompressible

Question 11

How significant is air density change due to pressure at subsonic flight?

Answer 11

Negligible

Question 12

Is air truly incompressible in subsonic flight?

Answer 12

No it’s just negligible so ignored

Question 13

What is transonic flight?

Answer 13

Subsonic and supersonic airflow

Question 14

What type of shockwave occurs in transonic flight?

Answer 14

Normal shcokwaves

Question 15

What do shockwaves cause in transonic flight?

Answer 15

Stability challenges & causes airflow separation from wing
Causes nose down pitch tendency

Question 16

Define supersonic flight?

Answer 16

All speeds on aircraft are greater than the speed of sound

Question 17

What speed is hypersonic?

Answer 17

Above Mach 5

Question 18

Where is the shockwaves during supersonic flight?

Answer 18

Shockwaves moves to rear and is affixed to trailing edge

Question 19

What happens to pressure and air density during supersonic flight?

Answer 19

Slight change in pressure and almost no change in air density observed

Question 20

Can air pressure change without air density changing?

Answer 20

Yes

Question 21

Is air compressible in supersonic flight?

Answer 21

Yes

Question 22

What compression effects develop during supersonic flight?

Answer 22

Reduction in coefficient of lift and an increase in coefficient of drag in the supersonic range

Question 23

How do you calculate Mach no. ?

Answer 23

Velocity(true airspeed) / local speed of sound

Question 24

What is critical Mach no. ?

Answer 24

Lowest mach no. at which airflow at some point reaches the speed of sound but does not exceed it