[JohnAB]

Hello,


I want to understand if I can replace a 36in diameter straight pipe, by 2x18in diameter straight pipes, in order to get a similar air flow rate through the system.

In reality it seems to me that linear losses are invitable, and are multiplied as I divide the diameter of the pipes. The 2x18in solution would provide a lower flow rate, and at best, the same flow rate than 1x36in.
Meaning the best solution is 1x36in, and that's it.

But, what kind of losses (small % or significant loss?) are we talking about by switching to 2x18in? That is what I am trying to find out using starccm+.

If know there are some empirical formulas about pipe line losses / linear losses through pipes of length L, but I would like starccm+ to help me confirm that, yes, I am actually losing X volume/second in flow rate by multiplying the number of pipes and making each diameter smaller.

Did anyone successively run a similar case?

thanks!

[Maddin]

https://en.wikipedia.org/wiki/Pressure_drop

Pressure drop is related inversely to pipe diameter to the fifth power.[7] For example, halving a pipe's diameter would increase the pressure drop by a factor of 2^5 = 32 (e.g. from 2 psi to 64 psi), assuming no change in flow.