I was trying to simulate the change in species (uds) concentration profile due to distance-interactions with an obstacle in the middle of my domain (mesh is shown below).

Distance interactions are simulated via an extra convection term, using DEFINE_UDS_FLUX. When I set all boundaries as wall and force the fluid to be stagnant, the simulation goes fine. However, in the actual case study I need to simulate, I have a top-and-bottom periodicity. So I reset Fluent and changed the top and bottom boundary conditions to periodic (using mesh>modify-zones->make-periodic). Fluid was still stagnant, and left and right boundary conditions were kept as wall. I built and loaded the library again without compilation warnings or errors. But when I run the simulation, the following error appears:


999999: mpt_accept: error: accept failed: No such file or directory


Fluent window is then automatically closed and I need to reopen my case from the workbench. When I reopen Fluent, unload/reload the library and then run the simulation, a new error message appears:


Error: floating point exception


This time my window is not automatically closed, but the same error keeps showing whenever I try to run my simulation. Some extra info:

1) Error is still there even when I choose to run with only 1 processor

2) If I change the top and bottom BCs to symmetry, simulation runs fine

3) If I do not hook DEFINE_UDS_FLUX, simulation runs fine


Any thoughts on this issue would be really appreciated.