Flow bypass 1

[mielke]

Does anyone know a good way to predict how much gas flow will bypass in a syste. For example We have a duct mostly filled with a pourous medium but there are some gaps around the perimiter of the duct. How can we figure out how much gas flow will actually go through the pourous medium and how much will excape through the gaps.

Thank You

 

[cloa]

Wrong Forum- You want Pipeline, Piping and fluid mechanics.
You are going to need a lot more details like dimensions of respective parts of the system and aerodynamic resistance of the porous medium or its composition.

 

[MrBTU]

In the shell and tube heat exchanger world, we have used factors based on experience and testing. Now a days, there are excellent cfd (computational fluid dynamics) programs and firms that will model your specific situation and predict with considerable accuracy how much flow will go through the medium. However, like FEA and other computational methods, the output is only as good as the input.

 

[vpl]

mielke

Remember that fluids, whether gas or liquid, seek the path of least resistance. As a first order you could try calculating the pressure drop across the gap and then compare it to the pressure drop for the porous medium (which hopefully the manufacturer has provided to you).

However, as cloa said, a lot more information would be needed and, as Mr. BTU said, a cfd computer program would probably be helpful.

From a practical standpoint, if you want the gas to go through the porous mediume, use sealant strips and plug the gaps.

Patricia Lougheed

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