Results conflicts with boundary conditions
 

Hi, I was running a simulation with a burner adjacent to a plate. (close contact) Both of them are in the center of the domain.

Both of them are extruded with top and bottom patches. For the plate, both patch velocities are set to zero. For the burner, the bottom patch velocity is set to zero, and the top patch is set with "flowRateInletVelocity".

To my surprise, in the results, although most combustion occurs on the top which is reasonable, some of the combustions indeed occur below the burner and plate. It seems there is no "wall" boundary condition at the burner so that some fuel diffuse across it. For plate, I can see there is a "wall".

So I am wondering if the "flowRateInletVelocity" allows flow across it? And anyone could help and suggest a reasonable boundary condition for the burner