Pressure drop correlations in pipeline 1

[Dan81]

Hallo to everybody! I'm searching information about pressure drop correlations and friction factors! I think the best way is to talk with people who deal with this problem every day! So...if you can help me...I need information on pressure drop methods pipeline correlations (such as AGA, Panhandle, Weymouth and Oliphant) or friction factor moedels (like beggs-brill, dukler, lokchart-martinelli) like range of using, formula and so on...

Thank you very for the attention and the help!

P.s.: Is the aga formula only good for one phase flow?

 

[CRG]

There is a good discussion of this in GPSA Engineering Data Book.

 

[DrillerNic]

Most of the single step methods (Panhandle A, Weymouth etc) are empirical correlations for single phase gas flow in pipelines which try to find a value for the 'Transmission factor', (1/F)^1/2, where F is the Fanning Friction factor in the general energy equation. This transmission factor collects pressure losses due to friction and all non ideal gas behaviour etc.

I was told to use either the Weymouth or the Panhandle A for quick & dirty gas pipeline hydraulics calculations. The Weymouth Equasion is supposed to be good for short pipelines and the error increases with pressure.

Friction factor models and flow maps such as Beggs & Brill etc really only apply to multiphase lines. Computer simulations use the general energy equasion and PVT simulators together to calculate gas pipeline hydraulics.

 

[1969grad]

For dry gas any of the Panhandle equations will work IF they are used within the proper Reynolds number ranges. That is why there are several Panhandle formulas. Each for a different range.

I use either the modified colebrook-white correlation for friction factor or the AGA equations. In my opinion, the colebrook-white correlation works best because you never have to worry what the Reynolds number is. With the AGA equations you have to check that you are in the fully turblent range or not.

For two phase flow the modified briggs and brill method works best for pressure drop calculations as it takes into account slip between the phases and because it can handle elevation changes. The briggs and brill correlation uses Moody friction factors.

However in selecting any two phase correlation an important consideration is the holdup correlation which is too broad a subject for discussion here. As I recall the Oliphant correlation is a hybrid equation for handling low holdup factors.

Sounds like your knowledge of two phase flow is very limited so I suggest you get some help. It is not a quick study.

BTW, Weymouth is way way too conservative for pipeline calculations.

 

[vzeos]

You may want to go to the attached site and check out paper 0112: - "A Tutorial on Pipe Flow Equations"

http://www.psig.org/Papers/archive.asp?year=2001&submit=Retrieve+Papers