How can i assign a set of data (table or matrix) as an input for source term?

reza.s · March 2, 2015, 07:07

Hi
I am simulating a channel flow in cfx and i need to add source term to continuity equation.in order to add mass source term i need to set its temperature.instead of assigning a constant temperature value for whole domain, i want to use a set of temperature values (like a temerature matrix) over my domain. my question is:

is it possible in cfx to assign a set of data as an input instead of a fix value or an expression? How can i do it?

I am new to cfx so please help me.
thanks in advance.

singer1812 · March 2, 2015, 09:48

Look up tables or functions. These are pretty easy to use, and you can even import a file with the values you want to use.

If you have further questions after reading up, please ask.

reza.s · March 2, 2015, 10:59

thanks singer1812 for taking your time and answering my question. I did as you said and looked up cfx document under user functions. as you said ,I can create a set of data including coordinates and quantity of interest and cfx will use interpolation to calculate values on nodes.

you said i can import file containing values i want, is it possible to use results of another cfx simulation (in the same geometry ) to generate such a file that can be used as input like you said?

thanks again.

Opaque · March 2, 2015, 12:12

If the results you require from a previous simulation can be associated to a post-processing locator such as a boundary, surface group, etc, you can use the export functionality in CFD-Post.

Select the BC export profile, customize it for the type of export you require and the .csv file written can be then imported into CFX-Pre.

You may need to read the CEL syntax details on how to hook up such .csv file.

reza.s · March 2, 2015, 19:25

thanks opaque for your reply.
what i want is not boundary condition. to add mass source term, I need to specify temperature for this added mass as an input. I want to use temperature field from a previous simulation as temperature required in mass source term tab in cfx .
Is it possible to this in cfx using the export functionality in CFD-Post that you mentioned?
thanks a lot.

Opaque · March 2, 2015, 21:31

It will export as you need. However, the file may be large and I am not sure about the performance of the software dealing with it.

I would try it in a coarse mesh first, and see if it work as you desire, and then go for the final mesh.

March 2, 2015, 07:07	How can i assign a set of data (table or matrix) as an input for source term?	#1
reza.s New Member Join Date: Mar 2015 Posts: 3 Rep Power: 11	Hi I am simulating a channel flow in cfx and i need to add source term to continuity equation.in order to add mass source term i need to set its temperature.instead of assigning a constant temperature value for whole domain, i want to use a set of temperature values (like a temerature matrix) over my domain. my question is: is it possible in cfx to assign a set of data as an input instead of a fix value or an expression? How can i do it? I am new to cfx so please help me. thanks in advance.

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March 2, 2015, 09:48		#2
singer1812 Senior Member Edmund Singer P.E. Join Date: Aug 2010 Location: Minneapolis, MN Posts: 511 Rep Power: 21	Look up tables or functions. These are pretty easy to use, and you can even import a file with the values you want to use. If you have further questions after reading up, please ask.

March 2, 2015, 10:59		#3
reza.s New Member Join Date: Mar 2015 Posts: 3 Rep Power: 11	thanks singer1812 for taking your time and answering my question. I did as you said and looked up cfx document under user functions. as you said ,I can create a set of data including coordinates and quantity of interest and cfx will use interpolation to calculate values on nodes. you said i can import file containing values i want, is it possible to use results of another cfx simulation (in the same geometry ) to generate such a file that can be used as input like you said? thanks again.

March 2, 2015, 12:12		#4
Opaque Senior Member Join Date: Jun 2009 Posts: 1,880 Rep Power: 33	If the results you require from a previous simulation can be associated to a post-processing locator such as a boundary, surface group, etc, you can use the export functionality in CFD-Post. Select the BC export profile, customize it for the type of export you require and the .csv file written can be then imported into CFX-Pre. You may need to read the CEL syntax details on how to hook up such .csv file.

March 2, 2015, 19:25		#5
reza.s New Member Join Date: Mar 2015 Posts: 3 Rep Power: 11	thanks opaque for your reply. what i want is not boundary condition. to add mass source term, I need to specify temperature for this added mass as an input. I want to use temperature field from a previous simulation as temperature required in mass source term tab in cfx . Is it possible to this in cfx using the export functionality in CFD-Post that you mentioned? thanks a lot.

March 2, 2015, 21:31		#6
Opaque Senior Member Join Date: Jun 2009 Posts: 1,880 Rep Power: 33	It will export as you need. However, the file may be large and I am not sure about the performance of the software dealing with it. I would try it in a coarse mesh first, and see if it work as you desire, and then go for the final mesh.