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-   -   HOMOGENEOUS TWO PHASE FLOW IN A PIPE (http://www.cfd-online.com/Forums/fluent/45512-homogeneous-two-phase-flow-pipe.html)

beginner July 25, 2007 15:38

HOMOGENEOUS TWO PHASE FLOW IN A PIPE
 
Hello everybody

I would like to get the drop pressure in a vertical boiling pipe.

I am looking for somebody capable to explain me the link between the BLASIUS Law for friction in homogeneous (blubby flow) two phase flow in pipe and the drag coeficient NAUMANN which is proposed in fluent. Is it possible to get some data with fluent??? which model, parameters...

Conserning heterogeous (slug) i would like to know if somebody have already got some result considering some corelation as MARTINELLI NELSON ou FRIEDEL? May be with UDF.

Sorry i am just a beginner, hoping that my question will interest you.

Bye bb


K.Baker July 26, 2007 04:20

Re: HOMOGENEOUS TWO PHASE FLOW IN A PIPE
 
The Blasius law is very simple law to estimate the friction factors in the pipes from Rynolds number and there is different laws for it in laminar turbulent flow,smooth rough pipes...etc In FLUENT we not in need for it because the friction factors can be estimated directly from the shear stresses from the relation f(friction factor)=shear stress/(2*density*velocity^2)I am not sure If i wrote this relation correctly you can check it from any CFD book. So you can get the data from FLUENT? My interest also in two phase flow but I am studying stratified flow not bubbly so do you have an idea about the relations of predicting the pressure drop in two phase flow in general. Hope this helpful for you too.

K.Baker


beginner July 27, 2007 12:17

Re: HOMOGENEOUS TWO PHASE FLOW IN A PIPE
 
Hi sorry but i am would take to homogeneous two phase flow.

I have still some problem and now i come back to simple phase to simple phase flow. I don't get the roughness height i try to compare with MOODY diagramme.

If you have any information about this. I Would be very grateful



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