[Ionut G]

Hello all,

I need help regarding the command user_getvar.
I want to extract the velocity gradient using the command user_getvar.

I wrote a fortran code to compute the velocity in the boundary layer.
I compiled it using intel fortran compiler 14.0.3.202, it result 4 files including the .dll file which I need for ansys cfx but it gives me a warning, is it ok?
"ifort: command line warning #10161: unrecognized source type 'winnt-amd64\\stand
ard_wf.o'; object file assumed".

If I run the simulation with the files resulted by the compiler, the cfx solver stops returning with the following error:

Details of error:-
----------------
Error detected by routine MAKDIR
CDRNAM = VEL /GRADIENT
CRESLT = ILEG

Current Directory : /FLOW/ALGORITHM/ZN1/SYSTEM/VARIABLES

+--------------------------------------------------------------------+
| Writing crash recovery file |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine MEMERR |

In the fortran code, I want extract the velocity gradient like this:
"CALL USER_GETVAR('Velocity.Gradient', CRESLT, pGRAD_V, CZ,DZ,IZ,LZ,RZ)"

I attach the fortran code(standard_wf), the messages from compiler(compiler results), and the output file from solver(ansys error)

Thanks in advance for support.

[cfdgremlin]

I think you need to specify a velocity component, e.g.

CALL USER_GETVAR('Velocity u.Gradient', ................

CG

[Opaque]

I would try

'MyFluid.Velocity.Gradient'

as per the documentation

You should always add the fluid name even though, in some cases such as for the variable Pressure, it is not strictly necessary. The fluid name is required when specifying a phase-specific variable (in a multiphase case) and when specifying an algebraic Additional Variable (even for a single-phase case).

Keep us posted..

[Ionut G]

Hello cfdgremlin, thanks for the quick reply.

I have tried your suggestion, but it didn't work I have the same error.

[Ionut G]

Hello Opaque, thank you for the quick reply.

I called the user_getvar command like you recommended and the error it is gone.

Now I have another error (I did the simulation in both single precision and double precision):
+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction.
| Message: |
| Floating point exception: Invalid number |


+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction.
| Message: |
| Stopped in routine FPX: C_FPX_HANDLER
| |

Can you help me?

[ghorrocks]

This is a FAQ: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

I would check that your simulation runs OK without the custom wall function.

[Ionut G]

Hello Glenn,

Thank you for reply, I followed the instructions from FAQ section and it seems that the errors is from the fortran code.
I will post here when I will have a working code.

Thank you all for the support.

[Ionut G]

Hi,

After I searched a little more and after some conversations with Ansys Support, it seems that I can not replace the scalable wall function with a custom wall function.

I will move to Fluent, there I can implement a custom wall function.

Thank you all for the support.