Of course, I send the screenshots of the geometry, mesh, boundary conditions, interface zone. I used k-omega formulation for this problem. I used your method, i.e. putting the value of 1300 K, constant temperature on Patch. Since Fluent gives me the results I posted to you, I searched and I understood how to implement the algorithm in the field function, inserting it in Report Definition, but the algorithm I had formulated is wrong. Sorry if I have explained myself wrong: I had found how to put the algorithm, but I cannot find an exact formulation. Putting 1300 K ub the Patch, the fluid increases its temperature, while the solid remains at the same temperature. I also tried using Time step sizing -> automatic but without success.nn