Hello all, I am working on a problem consisting of an axially-horizontal cylindrical tank with an inlet (an opening) at its top and a connected pipe to its bottom as an outlet. The boundary conditions are set accordingly, i.e., inflow and outflow, respectively. There is no problem with isothermal simulation of such configuration. However, when volumetric heat source is added to the fluid domain (via userq2 subroutine), non-physical temperatures have been observed at the walls (w/ adiabatic BC) in the immediate vicinity of the inflow (w/ Dirichlet temperature BC). In fact, the element nodes close to the inlet have very high or very low temperatures, which are no expected. I am wondering if anyone has any experience/hint on this issue. Thanks, Mohsen