unphysical temp fluid/solid region
 

When modelling heat transfer between a solid and a fluid region unphysical temperatures appeared at the solid/fluid interface. I solved this by using the following (obtained from fluentusers solution 745):

rpsetvar 'temperature/secondary-gradient? #f

My question is what the above command really does?? It's not equivialent to solving the energy equation by first order upwind, or is it? thanks!