A simple real-world fluid dynamics question:

1. Oct 24, 2004

danoonez

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.

2. Oct 25, 2004

enigma

Staff Emeritus
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?

3. Oct 25, 2004

danoonez

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.

4. Oct 25, 2004

naveen

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.

5. Oct 25, 2004

danoonez

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

6. Oct 25, 2004

enigma

Staff Emeritus
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.

7. Oct 25, 2004

danoonez

They will all be mandrel bends.

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