[ym5152]

Hi guys.
I am conducting a heat sink analysis in a natural convection situation.
As a result of checking several papers, the temperature on the bottom side of the heat sink with heat flux is high, so the flow starts from the bottom, enters the heat sink through the side of the heat sink, and exits to the top of the heat sink. But when I actually do CFD, the main flow comes down from the top of the domain and goes into the top of the heat sink.

If anyone has proceeded with a similar problem, I would appreciate it if you could let me know how to solve it.

The working fluid is set to incompressible ideal gas, and the boundary condition is pressure inlet on the top and bottom of the cylindrical domain and the side of the pressure outlet. The viscous model is using laminar and RNG k-epsilon.