[Vitaly]

Hello,

I am writing a UDF to obtain the wall shear stress gradient.

If I have a WSS on a single face, I have an algorithm for finding the gradient based on the WSS of the surrounding faces.

Is there a macro to automatically identify surrounding faces?
Thanks,
Vitaly

[dfytanid]

Hello Vitaly!

A good idea would be to store Wall Shear Stress (WSS) Values in UDS and after that use UDSI_G in order to access WSS gradient values.

Good work!

[Vitaly]

Hello,

I am not sure how to get the WSS values. Do I have to calculate them or does Fluent allow me to just access them like I can access temperature values using F_T(f,t)?

I am getting confused by the macros in Fluent because some of them are not listed in the (very long) manual. Examples in the manual use macros that are never explained or defined (e.g. SV_UDS_I...what is that???). Is there a location where all these little things are explained?

It would be nice if there was an extensive list of macros and descriptions.

The ANSYS documentation is completely amateurish!!!

Thanks,

Vitaly

[Azi Lotfi]

Hi

Does anyone here know how to write a udf to calculate time-averaged wall shear stress gradient (TAWSSG)?

Any suggestions would be much appreciated

cheers

[gearboy]

Originally Posted by Vitaly

Hello,

I am writing a UDF to obtain the wall shear stress gradient.

If I have a WSS on a single face, I have an algorithm for finding the gradient based on the WSS of the surrounding faces.

Is there a macro to automatically identify surrounding faces?
Thanks,
Vitaly

You can use the below macro to get the shear force on wall.

NV_VS(shear_force,=,F_STORAGE_R_N3V(f,tf,SV_WALL_S HEAR),*,-1); //F_STORAGE_R_N3V(f,tf,SV_WALL_SHEAR) is the fluid's force, so multiply -1 to get force on wall