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### Pressure drop in a compressed air system (assignement)

Posted: Thu Sep 19, 2019 7:55 am
Good day all, i need help to solve some points of this exercice!

The candiate has to size the loop ring pipe and primary air receiver AS1 in a compressed air system given that
• Standard conditions
• Compression ratio 7
• Max pressure drop in the loop 0.1 bar
The attachment graph1.png is no longer available
The first part has been solved
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My problem come after calculating the pressure drop using the following formula

dP= 1,6*10^8*[(L*Qc^1,85)/(P*d^5)]
where:
Dp = pressure drop (bar)
QC = Air demand (m3/s of free air)
L = length (m)
d = internal diameter (mm)
p = pressure (bar) (abs)

the compression ratio is 7 so In my case P=7 bar
fad.png (34.86 KiB) Viewed 19540 times
This table displays the results of the professor
I can’t find the same value of the pressure drop in branch 1 and 3 (colored in yellow)

Any help would be highly appreciated!