Heat Exchanger with multiphase

Carno · January 31, 2017, 04:33

Hi,

I am trying to simulate a Heat Exchanger which has 3 domains viz. air, water and solid. I have switched on multiphase - mixture option since I want to simulate boiling. I have 3 fluids (air, liquid water P1, vapor water P2) and 1 solid in materials.

Problem: Now, I am not able to assign air to the air domain in cell zones. The options of material available are, mixture, phase-1 and phase-2. Air is missing.
Same thing is happening in boundary conditions. Everything is ok in water domain.

Please help.

regards,
carno

Carno · February 3, 2017, 02:40

If I switch off the multiphase I can clearly select the air and water from material pull down. As soon as I switch on multiphase, the only options remained are, mixture, phase-1 and phase-2. How to select air which is not a phase. Shall I create one more phase as air (total 3 phases) making liq. water, vap. water and air as three phases. Then how about mixture BCs? Will that get applied to air also, as this is a phase of the mixture?

Please help.

Ansys has a case study of EGR cooler, which is perfect example. But in that they have not showed the material selection. In the video, there is short glimpse of material dialogue box, which showed mixture for EGR which is not a mixtre (Phase changing fluid). Check the video here. https://www.youtube.com/watch?v=EXO85d2eEOw

January 31, 2017, 04:33	Heat Exchanger with multiphase	#1
Carno Member carno Join Date: Mar 2009 Posts: 70 Rep Power: 17	Hi, I am trying to simulate a Heat Exchanger which has 3 domains viz. air, water and solid. I have switched on multiphase - mixture option since I want to simulate boiling. I have 3 fluids (air, liquid water P1, vapor water P2) and 1 solid in materials. Problem: Now, I am not able to assign air to the air domain in cell zones. The options of material available are, mixture, phase-1 and phase-2. Air is missing. Same thing is happening in boundary conditions. Everything is ok in water domain. Please help. regards, carno

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February 3, 2017, 02:40		#2
Carno Member carno Join Date: Mar 2009 Posts: 70 Rep Power: 17	If I switch off the multiphase I can clearly select the air and water from material pull down. As soon as I switch on multiphase, the only options remained are, mixture, phase-1 and phase-2. How to select air which is not a phase. Shall I create one more phase as air (total 3 phases) making liq. water, vap. water and air as three phases. Then how about mixture BCs? Will that get applied to air also, as this is a phase of the mixture? Please help. Ansys has a case study of EGR cooler, which is perfect example. But in that they have not showed the material selection. In the video, there is short glimpse of material dialogue box, which showed mixture for EGR which is not a mixtre (Phase changing fluid). Check the video here. https://www.youtube.com/watch?v=EXO85d2eEOw