[Abhijeeth]

I would like to find the velocity values of neighboring cells, to find the derivative of velocity with respect to the radial direction.
I have an idea of finding the data of neighboring cells using the Thread pointer.
But does not have an idea how to code it.
Please share if u have any ideas.
Thanks in advance............

[sbaffini]

The UDF manual (or whatever its name is today) has examples of various loopings.

However, you don't need that because the gradient is among the available variables, then you can simply project that along your preferred direction

[Abhijeeth]

Originally Posted by sbaffini

The UDF manual (or whatever its name is today) has examples of various loopings.

However, you don't need that because the gradient is among the available variables, then you can simply project that along your preferred direction

Sir,
After using the gradient I got an error
MPI Application rank 0 exited before MPI finalize() with status 2

What needs to be done next .....................

[sbaffini]

Originally Posted by Abhijeeth

Sir,
After using the gradient I got an error
MPI Application rank 0 exited before MPI finalize() with status 2

What needs to be done next .....................

The problem you have could be anything, even non UDF related. Probably it is some floating point exception in one process, or you are using some variable which is not initialized correctly. Literally, it can be anything. Pretty sure there is some error in your UDF.

I suggest you to first make some experiments with examples you can find in the manual, and then adapt them to your needs.

However, some C coding capability is needed to proficiently use UDFs.