Learning Forum

[Hu Zhang]

When I was solving a mooring problem, I got an error as follow:

I can't figure it out even if I look up to the user manual.The parameters of floating body and mooring systerm from this essay((PDF) CFD simulation of floating body motion with mooring dynamics: Coupling MoorDyn with OpenFOAM (researchgate.net))

I'd appreciate it if anyone could help.

[Mike Pettit]

Hello,

This may be due to the nonlinear catenary cable settings. The Aqwa solver tries to create a database of horizontal and vertical tensions over a range of fairlead (Connection Point) positions, but the error message in your screenshot suggests that this calculation has failed (I appreciate this is not so obvious from the wording).

In the Cable details, you may need to adjust the Negative dZ Range of Expected Connection Point Vertical Motion (measured from the lowest anticipated database point to the Connection Point definition position) and Positive dZ Range of Expected Connection Point Vertical Motion (measured from the Connection Point definition position to the highest anticipated database point). You may also try reducing the Number of Vertical Partitions and Number of X Coordinates.

In the Catenary Section details, the Maximum Tension value (recently renamed as Maximum Expected Tension) should be set to the largest tension you expect the cable to experience - not the minimum breaking load (MBL) of the cable.

I hope this helps.

Mike