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View Full Version : A simple real-world fluid dynamics question:


danoonez
Oct24-04, 09:45 PM
It's not so simple to me being that I have no background in fluid dynamics, but it seems like it would be fairly simple for most mechanical engineers; anyway:

This is to help me with the design of my charge pipes in my custom turbocharger setup. Assuming a constant radius throughout, which would be more restrictive to the compressed air?

1) One 90 degree bend followed by a straight pipe followed by one more 90 degree bend.

2) One 90 degree bend followed by a straight pipe followed by a 45 degree bend followed by more straight pipe and followed by one more 45 degree bend.

3) One 135 degree bend followed by a straight pipe followed by one 45 degree bend.

Thanks for anybody's input.

enigma
Oct25-04, 12:02 AM
It's not a simple problem.

Is the total turn 180 degrees, or are you merely shifting the flow over a bit (doing a +90 followed by a -90 e.g.)?

What diameter pipe? What pressure, temperature, etc.? How long is the straight pipe?

danoonez
Oct25-04, 01:24 AM
Hmm, I guess it's not as simple as I imagined.

The details you asked for:

It will be a full 180 degree turn

2.5" diameter pipe, approximately 70 degrees F., approximately 8 lb/in^2, the straight pipes inbetween the bends would be about 6" max.

naveen
Oct25-04, 02:45 AM
The best possible choice would definitely be a U-shaped pipe.
Neither of the ones u mentioned cos u wanna change its direction by a full 180 degrees.

danoonez
Oct25-04, 02:05 PM
The best possible choice would definitely be a U-shaped pipe.
Neither of the ones u mentioned cos u wanna change its direction by a full 180 degrees.

Unfortunately, a full 180 degree bend is not possible b/c of space constraints.

enigma
Oct25-04, 02:15 PM
In that case, you will want the turns to be as smooth as possible.

Keep all hard edges out of it if at all possible.

danoonez
Oct25-04, 02:34 PM
In that case, you will want the turns to be as smooth as possible.

Keep all hard edges out of it if at all possible.


They will all be mandrel bends.