Different conductivities for a SINGLE domain for CHT problem in CFX

Mehul · August 2, 2012, 07:24

Hello CFX users,

I have a particualr CHT problem, where I have to specify different conductivity to a single domain. The reason is that, I have already created a def file and run the problem. Based on the results, I have to change thickness of the domain. The domain is made of insualtion. and my probelm is, if I increae insualtion thickness, it will help me satisfying design criteria. So, changing insulation thickness is solution for me. Now I do not want to remesh it. For that, I am planning to change conductivity of the domain, which will take into account of thickness. But I have to chnage the thickness at few places only, because I am plannig to increase at few places only. Do we have any option in CFX where I can specify different conductivity in a single domain, so that I can keep same k for some region and different k for another region in a single domain.

ghorrocks · August 2, 2012, 21:25

You can make thermal conducitivity a function of location, or you can define different materials and make some constant k and some variable k.

But I would not take this short cut and properly model the increased insulation thickness in the geometry. This can be made parametric so you do not need to manually redraw and remesh.

Mehul · August 3, 2012, 02:11

Thanks Glenn.

In fact, I also run the whole analysis with properly modelling insualtion thickness. My intention to run with this short cut method i.e. different conductivity is to save process time, as this is a iteravtive process, and it might be possible that it does not satisfy criteria even till 5 to 6 iterations. But could you let me know, how we can make this process parametric in CFX. As far as my knowledge is concerned, there is no option we can make parametric atleast in CFX.

-Mehul

ghorrocks · August 3, 2012, 10:01

The whole idea of workbench is to allow parameters to drive geometry generation, meshing, setup and solution. Go to the ANSYS customer portal and have a look at the workbench parametrisation tutorials.

August 2, 2012, 07:24	Different conductivities for a SINGLE domain for CHT problem in CFX	#1
Mehul New Member mehcaecfd Join Date: Mar 2009 Location: Bangalore Posts: 3 Rep Power: 17	Hello CFX users, I have a particualr CHT problem, where I have to specify different conductivity to a single domain. The reason is that, I have already created a def file and run the problem. Based on the results, I have to change thickness of the domain. The domain is made of insualtion. and my probelm is, if I increae insualtion thickness, it will help me satisfying design criteria. So, changing insulation thickness is solution for me. Now I do not want to remesh it. For that, I am planning to change conductivity of the domain, which will take into account of thickness. But I have to chnage the thickness at few places only, because I am plannig to increase at few places only. Do we have any option in CFX where I can specify different conductivity in a single domain, so that I can keep same k for some region and different k for another region in a single domain.

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August 2, 2012, 21:25		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	You can make thermal conducitivity a function of location, or you can define different materials and make some constant k and some variable k. But I would not take this short cut and properly model the increased insulation thickness in the geometry. This can be made parametric so you do not need to manually redraw and remesh.

August 3, 2012, 02:11		#3
Mehul New Member mehcaecfd Join Date: Mar 2009 Location: Bangalore Posts: 3 Rep Power: 17	Thanks Glenn. In fact, I also run the whole analysis with properly modelling insualtion thickness. My intention to run with this short cut method i.e. different conductivity is to save process time, as this is a iteravtive process, and it might be possible that it does not satisfy criteria even till 5 to 6 iterations. But could you let me know, how we can make this process parametric in CFX. As far as my knowledge is concerned, there is no option we can make parametric atleast in CFX. -Mehul

August 3, 2012, 10:01		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	The whole idea of workbench is to allow parameters to drive geometry generation, meshing, setup and solution. Go to the ANSYS customer portal and have a look at the workbench parametrisation tutorials.