force monitor flat-lining

i ran a simulation of seawater flowing at a constant 20 MPH over a fin cluster in a closed volume, resulting in what looks like very reasonable pressure and Cp color maps. The Force monitor for x direction (drag) is zero everywhere though. I attached the monitor to the "group" representing my fins. Does anyone have any clue what i might be doing incorrectly here?

Single Flow Volume?

Did you subtract your fins from the flow volume to form a single volume for the fluid around your fins? For more details try the section "Single Volume Required" at "RANS Flow."

moving geometry

Mahalo for the advice, you helped me figure it out. Hey, one more question related to this if you don't mind: is it possible to vary the volume geometry over time? For example, i want my fins to have 0 deg. angle of attack at t=0, and -4 deg at t=30. I cannot accomplish this by simply changing the flow direction because the fins are mirrored about XZ plane (4 fins, 2 per side). I tried making my geometry by rotating them -4 deg @ t=30, but when i subtract the volumes, i am only left with the initial state (alpha=0). Sorry if this sounds confusing... Any advice or comments will be much appreciated...!

No moving geometry for RANS Flow

Currently Caedium does not support moving/deforming geometry for RANS Flow simulations.

I suggest constructing multiple flow volumes matching each variation. Alternatively you could simulate the full configuration (no symmetry) and just vary the flow direction.