Total Pressure In Branched Ducts

[samanchek]

Hi, I believe this is the right place for this...I am wondering if you have a duct that splits into two seperate branches then how does the total pressure in the original duct relate to the total pressure in the two branches? Does Po = P1 + P2, Po = P1 = P2 or some other relationship?

Thanks

 

[ChasBean1]

No, pressure in the main duct is the exact same as pressure in the branch ducts (Pascal's Law). With air flowing however, pressure in each downstream branch will be slightly lower due to friction losses. You're thinking of flow. Flow in the main will equal the sum of the sub-branches.

 

[ChasBean1]

(scratch the Pascal's Law statement - similar concept meaning pressure will be equal throughout barring flow, but Pascal's is applicable to incompressible fluids)

 

[Unotec]

Actually, if the branches have a smaller diameter, the pressure on them will be lower right from the start. For the exact same reason Chasbean1 quoted. Being a compressible fluid, the pressure will drop due to the diameter (and direction) change.

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