After the boundary conditions were fixed, I got a new drag. However, the average drag is still negative. Reviewing the case setup, I found this:

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dragDir         (0 1 0);

The drag direction was set to be in the y-direction. That’s the reason why is negative. After, fixing it, the drag should be in a positive value.

Next, I will set up the projection area, the reference length, and the unit properly. From there, we can do more interesting comparisons.