[Mohamed Abdulazim]

Hello everybody,
I am trying to solve a heat transfer problem(conjugate heat transfer )by the fluent, which is a heat transfer enhancement in a rectangular channel with baffles. The problem is a rectangular channel with a 1 m length and there is heating by constant heat flux from the above and lower plates(The aluminium heating plates are 3 mm in thickness) in the channel and there are solid baffles in a staggered arrangement on the lower and upper plates. During my calculations, I noticed that there is a reverse flow in many faces(about 1750 faces) at the pressure outlet, this number started small at the 25th iteration and increased to 1750 faces at the 450th iteration and remained constant after that. Before the exit section, there is a baffle on the upper surface and it is about 5 cm away from the exit section. I think this small distance between the baffle and the exit section is the main cause of reverse flow at the outlet, so I need to shift the exit section with enough distance from the baffle to prevent this phenomenon, What should I do in order to do this without any effects on the boundary conditions and the calculations?
Thanks in advance.