CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Question about mass flow export in element face (

Jaemin Park September 22, 2011 04:18

Question about mass flow export in element face
Glad to see you guys, I'm turbine engineer and I have some questions about ANSYS CFX-post.

I want to export the mass flow rate from every mesh element's faces. In my case, all mesh is hexahedral so there are 6 faces in each elements. In the export tools in CFX-post, I can export the information at the node only, not at the control volume or element volume or element faces.
Is it possible? If it is possible, how can I export that informations?

Thank you for read. Have a nice day!

ghorrocks September 22, 2011 06:11

I don't think you can export data from anything except the nodes. The nodes are the only location where the variables are stored.

You might be able to get something out of the export options in the solver manager (under tools), but no guarantees.

michael_owen September 22, 2011 10:09

The data at the nodes ARE the data at the control volumess; that's what a node is, the center of the control volume, and the data stored there are averages over the control volume.

Jaemin Park September 22, 2011 19:44

Thank you ghorrocks, I will try to export from the solver CGNS options.

Jaemin Park September 22, 2011 19:46

Thank you for reply owen.
I know the node value is the average value for control volume.
But I want to know the inlet volume flow rate in each control volume, and that means I have to export the mass flow from every faces in each control volume.
node is just a point so mass flow value is 'null'.

ghorrocks September 23, 2011 07:36

I can't see a way of doing this. Why do you want to export the face mass fluxes?

Jaemin Park September 24, 2011 05:01

Thank you Glenn,

In my work, I have to devide the entropy generation for each flow region. I can't use the absolute entropy value of CFD results, because I can't get the entropy generation rate from absolute value. So I just calculate the entropy generation rate from turbulent dissipation epsilon. And then, I have to know the delta t(time) of each cell for integrating entropy generation. Delta t might be the ratio of each element's volume and volume flow rate ( (m3)/(m3/s) ).

I try to export the cgns type results from solver, but I also can't find the way to do.

ghorrocks September 24, 2011 06:24

I suspect you can do this inside CFD-Post with no need to export anything. But I do not know the detail of what you are calculating so cannot be sure.

You do the CGNS export in the solver manager, under tools/export.

All times are GMT -4. The time now is 22:03.