Heat transfer

oliveira1820 · February 11, 2019, 05:00

I am modelling the water inside a domain, heated by different energy sources.

I have designed geometric subdomains which will be used as reference to define energy sources inside those subdomains.

The problem is that, in CFX-Pre, the software assumes that there is a wall between the water domain and the energy sources subdmains, thus, resulting in the separation of the water inside the subdomains and the remaining domain.

How can I define the energy sources geometrically and tell the software that water occupies equally all the domain?

ghorrocks · February 11, 2019, 06:01

When you define the domain select both the main fluid region and the heat source regions. Then define a subdomain with just the heat source regions in it.

oliveira1820 · February 12, 2019, 04:05

I did exactly that but the software automatically defines a wall between the energy source domain and the remaining domain. (and I can´t delete it)

I want that water fills the entire domain equally, even on the subdomains location. The subdmains should only work as a geometric reference to the enerngy sources.

monkey1 · February 12, 2019, 11:33

What do you mean with "geometric subdomain"?
Two separate meshes?
If yes then you will have to define interfaces between the meshes and there you can select, that they should be "open"
If you have 2 (or more) meshes glued together without interfaces, then CFX-Pre will automatically set the contact surfaces as "wall"...

oliveira1820 · February 12, 2019, 14:28

I mean subdomais respective to the geometric cylinders I´ve designed, that correspond to differnet meshes yeah.

So, defining the interface as opening it is the same as if there was no interface at all, for heat, mass and momentum transfer?

February 11, 2019, 05:00	Heat transfer	#1
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	I am modelling the water inside a domain, heated by different energy sources. I have designed geometric subdomains which will be used as reference to define energy sources inside those subdomains. The problem is that, in CFX-Pre, the software assumes that there is a wall between the water domain and the energy sources subdmains, thus, resulting in the separation of the water inside the subdomains and the remaining domain. How can I define the energy sources geometrically and tell the software that water occupies equally all the domain?

February 11, 2019, 06:01		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	When you define the domain select both the main fluid region and the heat source regions. Then define a subdomain with just the heat source regions in it. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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February 12, 2019, 04:05		#3
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	I did exactly that but the software automatically defines a wall between the energy source domain and the remaining domain. (and I can´t delete it) I want that water fills the entire domain equally, even on the subdomains location. The subdmains should only work as a geometric reference to the enerngy sources.

February 12, 2019, 11:33		#4
monkey1 Senior Member Join Date: Jul 2011 Location: Berlin, Germany Posts: 173 Rep Power: 15	What do you mean with "geometric subdomain"? Two separate meshes? If yes then you will have to define interfaces between the meshes and there you can select, that they should be "open" If you have 2 (or more) meshes glued together without interfaces, then CFX-Pre will automatically set the contact surfaces as "wall"...

February 12, 2019, 14:28		#5
oliveira1820 Senior Member Pedro Oliveira Join Date: Feb 2018 Location: Portugal Posts: 109 Rep Power: 8	I mean subdomais respective to the geometric cylinders I´ve designed, that correspond to differnet meshes yeah. So, defining the interface as opening it is the same as if there was no interface at all, for heat, mass and momentum transfer?