In your nodal coordinate defintion (Node#1 ~ Node#11) and the tube element definition,Â the tubes' axial axis is on the mean water surface andÂ along x-direction.Â Â

The force and moment are output with respect to the COG of the structure, i.e. (Xg, Yg, Zg).Â If you want the moment to be output with respect to another reference point, i.e. (Xr, Yr, Zr),Â please manually do the calculation with the additional cross product term:

(Mrx, Mry, Mrz) = (Mx, My, Mz) + (Xr -Xg, Yr-Yg, Zr-Zg) x (Fx, Fy, Fz)

where (Mx, My, Mz) is the moment with respect to COG, (Fx, Fy, Fz) is the force with the respect to COG.

The translational drag and added mass coefficients can be input by CONT data record, see below and see 8.3. Geometric Property Data Record (ansys.com)

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