Explain clearly what do you understand by Fanno flow. Show its plot on h – s diagram and give its characteristics.
Air flows in an insulated duct with a Mach number of 0.2. The initial temperature and pressure are 290 K and 2.0 bar respectively.
Determine :
- the pressure and temperature at a section of the duct where the Mach number is 0.8.
- the distance between these two points if the duct diameter is 10cm and friction factor is 0.004.
- what will be the maximum length of the duct to avoid choking? 30
use the following table.
|
M
|
P/P*
|
T/T*
|
4$\overline{f}L_{max}$/ D
|
|
0.2
|
5.455
|
1.19
|
14.533
|
|
0.8
|
1.289
|
1.064
|
0.073
|