Stratified flow mixing with water

Dragonuser · December 10, 2014, 22:40

Hello, everyone. Recently I want to do a simulation on the mixing of two pipes.
The main pipe contains stratified flow and the branch pipe contains sub-cooled water. And condensation must be considerated.
I have read some papers and find that the NEPTUNE-CFD can do this, they used this to simulate the COSI experiment. But they have implemented many other models such as Large interface recognition model, three cells thick large interface method and so on.
Since I cannot obtain NEPTUNE_CFD(not open to others except EDF,CAE), I was wondering whether I can do things like this with other software like CFX ,or fluent or ccm+? And how? Should I also implement some models or should I just use the default model?
Thanks very much in advance.

ghorrocks · December 10, 2014, 23:34

CFX has extensive multiphase modelling capability so can probably do the simulation you describe. But you are describing a very complex multiphase model. It is not a simulation to be attempted by beginners.

Dragonuser · December 11, 2014, 01:16

I see. Is it possible that it can be done without implementing other models? ie, can I do that just with what it has in CFX?
Besides, if I just run a simulation without phase change, will it be more realistic to firstly run it out?

ghorrocks · December 11, 2014, 03:50

CFX has many multiphase models (mixing models, free surface models), and also has many phase change models. So it has the capability to model most flows.

You have not described what you are modelling so I cannot assess whether a model without phase change will be adequate.

Dragonuser · December 12, 2014, 22:16

Understood. I am now simulating an air-water stratified flow from main pipe mixing with water from branch pipe. I am using inhomogeneous free surface flow, but it cannot converge, I was just wondering how I can do something like this. I read something about the LIM(Large Interface Model) in Neptune _CFD. Is there something like LIM in CFX since I cannot get Neptune _CFD code.
[IMG]http://a2.qpic.cn/psb?/V10drRp30jvf3u/xaoY2H4JfrYkATyF*i04FHMtThN92ETFQaqvfASCuDs!/m/dNPUIuMsAAAAnull&bo=vgL6AAAAAAAFB2I!&rf=photolist& t=5[/IMG]

ghorrocks · December 13, 2014, 06:09

I am not familiar with the large interface model or with Neptune CFD.

Have a look in the CFX documentation and see if the models it has available are suitable for you.

December 10, 2014, 22:40	Stratified flow mixing with water	#1
Dragonuser New Member KaiWang Join Date: Nov 2014 Posts: 11 Rep Power: 11	Hello, everyone. Recently I want to do a simulation on the mixing of two pipes. The main pipe contains stratified flow and the branch pipe contains sub-cooled water. And condensation must be considerated. I have read some papers and find that the NEPTUNE-CFD can do this, they used this to simulate the COSI experiment. But they have implemented many other models such as Large interface recognition model, three cells thick large interface method and so on. Since I cannot obtain NEPTUNE_CFD(not open to others except EDF,CAE), I was wondering whether I can do things like this with other software like CFX ,or fluent or ccm+? And how? Should I also implement some models or should I just use the default model? Thanks very much in advance.

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December 10, 2014, 23:34		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	CFX has extensive multiphase modelling capability so can probably do the simulation you describe. But you are describing a very complex multiphase model. It is not a simulation to be attempted by beginners.

December 11, 2014, 01:16		#3
Dragonuser New Member KaiWang Join Date: Nov 2014 Posts: 11 Rep Power: 11	I see. Is it possible that it can be done without implementing other models? ie, can I do that just with what it has in CFX? Besides, if I just run a simulation without phase change, will it be more realistic to firstly run it out?

December 11, 2014, 03:50		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	CFX has many multiphase models (mixing models, free surface models), and also has many phase change models. So it has the capability to model most flows. You have not described what you are modelling so I cannot assess whether a model without phase change will be adequate.

December 12, 2014, 22:16		#5
Dragonuser New Member KaiWang Join Date: Nov 2014 Posts: 11 Rep Power: 11	Understood. I am now simulating an air-water stratified flow from main pipe mixing with water from branch pipe. I am using inhomogeneous free surface flow, but it cannot converge, I was just wondering how I can do something like this. I read something about the LIM(Large Interface Model) in Neptune _CFD. Is there something like LIM in CFX since I cannot get Neptune _CFD code. [IMG]http://a2.qpic.cn/psb?/V10drRp30jvf3u/xaoY2H4JfrYkATyF*i04FHMtThN92ETFQaqvfASCuDs!/m/dNPUIuMsAAAAnull&bo=vgL6AAAAAAAFB2I!&rf=photolist& t=5[/IMG]

December 13, 2014, 06:09		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	I am not familiar with the large interface model or with Neptune CFD. Have a look in the CFX documentation and see if the models it has available are suitable for you.