Compressible Simulation: Results seem Wrong

[jakob77]

Hello,

I want to simulate a compressible, turbulent flow from a circular inlet (similar to engine outlet) slightly above the ground. I want to investigate the forces, especially in upward direction, that will act on a flat plate on the ground that is laying behind the inlet. My results for the lift force seem way too high, I get -750kN for a flow velocity of 200m/s. I think my setup is incorect, besides that the convergence plots dont seem to have a good quality. Does anyone know if my suspicion of wrong results is correct and how I can fix it?

Mesh:

Velocity Inlet Conditions:

Convergence Plot for the Domain:

My force plot:

Here is the link to my Project: compressible flow on plate | SimScale Workbench

I would really appriciate help, Thanks in advance for your answer.

[RicardoParis]

Hi,

Since this panel is attached to the ground (i.e. there’s a top face but there is no bottom face), the forces and moments result control gives you about 750 kN in Z because the top surface area is around 7.5 m2 and the pressure is close to 1 atm (101325 Pa * 7.5 m2 is about 750 kN).

Of course in reality you wouldn’t have vacuum under the panel, so there would be a similar force on the other side counteracting the top face.

Since you don’t have any bottom face at the moment, the Z force is artificially high.

Cheers