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Restriction calculation on elbows in intake system

Restriction calculation on elbows in intake system

Restriction calculation on elbows in intake system

(OP)
Man my schooling has failed me. I am trying to build a spread sheet that encompass the about of restriction a 45 and 90 degree elbow will place in an intake system. I have the engine intake air velocity and all the variable but for the life of me I can not get a number that makes sense. The minor system losses aren't coming out to be what I expected (nor what we see in the field with actual equipment) my results are an order of magnitude off.

Any direction or references would be appreciated.

Engineering has always been my love, but it ended up being my second career...

RE: Restriction calculation on elbows in intake system

That is a very non-specific question so it is difficult to give specific advice. If you want to read some background on minor pressure losses in pipe fittings and to get equivalent length data for 90 degree and 45 degree elbows you can read a couple of articles I have written at http://www.katmarsoftware.com/aioflo-articles-inde...

Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com

"An undefined problem has an infinite number of solutions"

RE: Restriction calculation on elbows in intake system

If you are trying to calculate the flow losses in a recip engine intake manifold runner, the problem is quite complex. The flow velocity and restrictions are not constant. The flow area at the intake valve is constantly changing, and the flow velocity is also changing in relation to the piston motion.

RE: Restriction calculation on elbows in intake system

(OP)
This is for a turbo charged diesel 4 stroke engine in a marine application. This is from the outside of the engine room to the turbo.

The calculations I am coming up with using a k values for the bends is obnoxiously high. I want to figure out the psi increase through the 3 different styles of 90s and 45s. This should be doable but I am brain-flatulating and it has been years since fluids and thermo.

so this problem is before the turbo and the engine manifold system.

Engineering has always been my love, but it ended up being my second career...

RE: Restriction calculation on elbows in intake system

Show us your calculations.

RE: Restriction calculation on elbows in intake system

Are you using a Crane (piping) book values, or an air flow value book?

RE: Restriction calculation on elbows in intake system

(OP)
Pounded away and got it guys thanks

Engineering has always been my love, but it ended up being my second career...

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