Piping loss with air-turbocharger 1

[kilrbee]

Air at 1000 CFM 80 degrees, sea level, enters a turbocharger for compression. Exits the compressor at 500 F, 32 psig, enroute to the CAC.

What is the air pressure loss for 4 feet (one sweep 90) of:

1.75" id pipe
2.5" id pipe

Thanks all.

 

[kilrbee]

oops, sorry for the typo. Compression is 18 psi, 32 absolute.

 

[Latexman]

Is this homework?

Is the sweep 4' long? If not, what's r/d?

Good luck,
Latexman

 

[kilrbee]

I'm a little old for homework, one sweep , a 6" radius will suffice.

 

[Latexman]

1.75" id pipe: dP = 15.9 psi. Flow is sonic and T = 386 F at the exit.

2.5" id pipe: dP = 1.02 psi.


Good luck,
Latexman

 

[Latexman]

That was the adiabatic solution.

Good luck,
Latexman

 

[kilrbee]

WOW! That is a bit shocking.

Can you give me an idea how you did the calc, or which tables you used.

FYI, this is a turbocharger application. What you are saying is that the turbo would have to work to produce 15.9 psi, just to get the compressed product through this pipe.

(BTW this pipe leades to the charge air cooler, where the charge is air-air cooled to 180 degrees.)

 

[Latexman]

I plugged the numbers into my handy dandy spreadsheet, that's how I did it.

The spreadsheet is based on adiabatic compressible flow equations in Shapiro's "The Dynamics And Thermodynamics of Compressible Fluid FLow".

Good luck,
Latexman

 

[kilrbee]

ok. How do I get a copy? Is it on cd somewhere? Or is it a formula out of a book?


Or if someone else can point me in the right direction to "learn how to fish" I would be grateful.

 

[Latexman]

There are many, many fluid flow and thermo books that have the equations for adiabatic pipe flow. Some other books that I know of are Perry's Handbook, McCabe and Smith's Unit Operations, Ron Darby's Chemical Engineering Fluid Mechanics, Crane Technical Paper 410, and my old college thermo book (1976) by Balzhiser, Samuels, and Eliassen. To be honest, a Chemical Engineer that doesn't know where to find this information is quite puzzling to me. Try searching Google for "adiabatic pipe flow". I got 39 hits. At least one should have the equations.

Good luck,
Latexman

 

[kilrbee]

LOL, I understand what you mean. I have my unit ops book right here. Covered with 15 years worth of dust.

Spent the last decade and a half doing everything but CN work.

Your tips have saved me a lot of time. Guess it is now time to reaquaint myself with these old books.

Thanks again

 

[Latexman]

CN?

Good luck,
Latexman

 

[Latexman]

Btw, what are you running 18 lbs of boost on with 1000 cfm? Must be a big block.

Good luck,
Latexman

 

[kilrbee]

Actually the 1000 cfm was an overshoot. More like 800 cfm, 18 psi, around 45-50 lb/min

Stock duramax turbo-diesel, 6.6 L

 

[kilrbee]

CN (chemical engineering) was differentiated from Civil Engineering (CE) at Lowell U