Nozzles, diffusers and thrusters

Question 1

What is a nozzle?

Answer 1

Increases the velocity of a fluid at the expense of pressure, KE.

Question 2

What is a diffuser?

Answer 2

Decreases the velocity by increasing pressure.

Question 3

What is the first law of steady state flow?

Answer 3

Total energy change is zero.
Rate of heat added Q(dot)
Rate of energy change at the inlet is m(dot)pheta1
Rate of energy change at outlet is -m(dot)pheta2
q(dot)-W(dot)2+m(dot)(pheta1-pheta2)=0

Question 4

What is a throttling valve?

Answer 4

A flow-restricting devices that cause a significant pressure drop in the fluid as well as temperature.