VISCOSITY UDF

AdN

Hello everyone!

I have again (and again) a question about UDF! This time, I try to modify viscosity in a region of my domain. When I interpret my function and initialise my pb, I can see (with display contour/molecular viscosity) that my initial viscosity is set correctly. But when i launch iterations (I'm in unsteady), everything goes wrong! I notice that my function is called twice per iteration! Can somebody tell me why?

P.S. In my function, i put conditions in that way the function will be called only on the first iteration of every time step. But as DEFINE_PROPERTY is called at every iteration, when we are at an other iteration than the first of a time step, there is no return statement in my function (in fact, the return is inside an "if" condition).