steam condensation bubbly flow

Dragonuser · November 24, 2014, 23:29

Hello again, everyone!
I am here looking for some suggestions in modeling bubbly flow with steam condensation.

The main pipe contains bubbly flow of 100-degree water and steam while the sub-pipe contains sub-cooled water as the fig indicates.

When they are mixed together, condensation of the steam must be considerated.
After everything has been set----

to be more specific, liquid is taken as the continuous phase while the gas as dispersed phase.
Drag forces and three non-drag forces are taken into consideration, and I used the phase change model.

Heat transfer model is two resistance with zero resistance for gas and Hughmark for liquid.

The iteration seems okay for the first like 200 interations. But after 200, I got overflowed.

And I found that the mass conservation is not very good since I monitored the liquid and gas at the outlet.

Can anyone tell me what is wrong here, if you need more information ,tell me and I will post my *.cfx.

BTW, I am using ANSYS 15.0.

Dragonuser · November 25, 2014, 03:49

Here the image[IMG]http://a2.qpic.cn/psb?/V10drRp30jvf3u/xaoY2H4JfrYkATyF*i04FHMtThN92ETFQaqvfASCuDs!/m/dNPUIuMsAAAAnull&bo=vgL6AAAAAAAFB2I!&rf=photolist& t=5[/IMG]

ghorrocks · November 25, 2014, 05:09

Don't bother posting your CFX file, I will not have time to look at it.

You are doing a very complex model so it is no surprise that you are having difficulties with it. It is the sort of model only people with many years of CFD experience should attempt.

Have you read the FAQ:
http://www.cfd-online.com/Wiki/Ansys...gence_criteria

http://www.cfd-online.com/Wiki/Ansys...gence_criteria

November 24, 2014, 23:29	steam condensation bubbly flow	#1
Dragonuser New Member KaiWang Join Date: Nov 2014 Posts: 11 Rep Power: 12	Hello again, everyone! I am here looking for some suggestions in modeling bubbly flow with steam condensation. The main pipe contains bubbly flow of 100-degree water and steam while the sub-pipe contains sub-cooled water as the fig indicates. When they are mixed together, condensation of the steam must be considerated. After everything has been set---- to be more specific, liquid is taken as the continuous phase while the gas as dispersed phase. Drag forces and three non-drag forces are taken into consideration, and I used the phase change model. Heat transfer model is two resistance with zero resistance for gas and Hughmark for liquid. The iteration seems okay for the first like 200 interations. But after 200, I got overflowed. And I found that the mass conservation is not very good since I monitored the liquid and gas at the outlet. Can anyone tell me what is wrong here, if you need more information ,tell me and I will post my *.cfx. BTW, I am using ANSYS 15.0.

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November 25, 2014, 03:49		#2
Dragonuser New Member KaiWang Join Date: Nov 2014 Posts: 11 Rep Power: 12	Here the image[IMG]http://a2.qpic.cn/psb?/V10drRp30jvf3u/xaoY2H4JfrYkATyF*i04FHMtThN92ETFQaqvfASCuDs!/m/dNPUIuMsAAAAnull&bo=vgL6AAAAAAAFB2I!&rf=photolist& t=5[/IMG]

November 25, 2014, 05:09		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	Don't bother posting your CFX file, I will not have time to look at it. You are doing a very complex model so it is no surprise that you are having difficulties with it. It is the sort of model only people with many years of CFD experience should attempt. Have you read the FAQ: http://www.cfd-online.com/Wiki/Ansys...gence_criteria http://www.cfd-online.com/Wiki/Ansys...gence_criteria