Hi!
To quickly answer your question, the “Forces and moments” plot which you posted above (figure 1) represents the sum of forces onto the model.
To me, the values that you found don’t look too weird. I can see that your model currently has an angle of attack of 0 degrees, so I’d expect little to no lift (or even negative lift) and a larger value for drag.
Some things worth noting:
- The tutorial that you posted was aiming for velocities > 0.3 Mach (where compressibility effects are not negligible). In your case, the velocities are far less than that, so using an Incompressible approach is not a bad idea.
- Running the simulation for more iterations is advised, as I can see that the forces are still shifting a little bit
- Apart from that tutorial, there’s also a workshop forum thread, which contains a similar tutorial for a wing (but using an incompressible approach instead). I’ll link it here in case you find it interesting: Workshop 2 Session 1: Optimization of a wing - Part II