[baymax_22685]

I am doing a simulation in which I am using udf to calculate a user-defined scalar through a transport equation. The scalar is based on shear stress which is available from the wall. I am interested in making those areas of the fluid domain where the scalar value reaches a critical value as walls/ boundaries(which are just near the wall in a thin strip).
However, I do not know the exact profile in which the region appears and hence cannot give an expression to the DEFINE_GRID_MOTION UDF expression.|
Can someone help?

Tl;dr: How to change the wall geometry in simulation, without knowing the exact expression for the motion and only the end profile, which is obtained from the simulation itself.