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-   -   different answers (http://www.cfd-online.com/Forums/fluent/104889-different-answers.html)

newminde July 18, 2012 02:00

different answers
 
Hi everyone, I have a problem with answers.
I'm doing tutorial https://confluence.cornell.edu/displ...+Specification
Velocity inlet 1m/s, RE=20.
If I open Ansys fluent and read a mesh, the result of drag coffiecient is 2.0427
If I open ansys workbanch and do the same the result is 2.14..
How is ot possible. Units SI.

Marion July 18, 2012 04:35

Hi,

Are you sure the settings in Fluent are the same? For example double precision vs. single precision? (I've had that recently!)

Marion.

cfd seeker July 18, 2012 04:59

Quote:

Originally Posted by newminde (Post 372039)
Hi everyone, I have a problem with answers.
I'm doing tutorial https://confluence.cornell.edu/displ...+Specification
Velocity inlet 1m/s, RE=20.
If I open Ansys fluent and read a mesh, the result of drag coffiecient is 2.0427
If I open ansys workbanch and do the same the result is 2.14..
How is ot possible. Units SI.

there is not too much difference between 2.04 and 2.14 values that you should worry about. But if at all you need an answer to your question it can be difference between the schemes which you are using for both simulations e.g solver settings, density based or pressure based, single or double precision and even reference values etc

flotus1 July 18, 2012 06:04

Do you mean that there is a difference when you do the POST-PROCESSING of the Fluent-calculation in Fluent directly and in the CFX-like result component in the workbench?
Now that would be a serious issue, although it is not surprising.

If you mean that the results are different when tha SIMULATION is conducted in Fluent and in CFX, this is nothing to worry about.


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