Available output channels from MoorDyn module

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Antonio.Pegalajar
Posts: 4
Joined: Mon Aug 15, 2016 10:21 am
Organization: DTU Wind Energy
Location: Kgs. Lyngby, Denmark

Available output channels from MoorDyn module

Postby Antonio.Pegalajar » Mon Aug 15, 2016 10:52 am

Hi,

I am trying to get out of a FAST simulation the (x,y,z) components of the mooring line tension for a floating wind turbine (semisub).

I have seen in the MoorDyn user guide (p.8 ) that e.g. the label "Con4pX" in the "OUTPUTS" section of the MoorDyn input file would give me the X position of one of the fairlead points. But when I try to get out the force by using "Con4fX", FAST crashes.

Is there another way to output the mooring forces? Thanks

Matt.Hall
Posts: 9
Joined: Tue Apr 05, 2011 2:41 pm
Organization: University of Prince Edward Island
Location: Charlottetown, PEI, Canada
Contact:

Re: Available output channels from MoorDyn module

Postby Matt.Hall » Tue Aug 16, 2016 8:29 am

Hi,

What version of FAST and MoorDyn are you using? I didn't have all the output channels set up in the first MoorDyn versions, but the "Con4pX"-type outputs should be working in the latest version.

If updating doesn't solve the problem or you're already using the latest version, let me know what error message you see and I'll try to help.

Cheers,
Matt

Masih.Vahid
Posts: 4
Joined: Fri Jun 16, 2017 10:10 am
Organization: University of Stuttgart
Location: Germany

Re: Available output channels from MoorDyn module

Postby Masih.Vahid » Thu Sep 14, 2017 3:39 am

Hi Matt,

I'm using MooorDyn to model s triple spar platform but I'm having problems on getting the forces on the fixed and vessel points in X,Y and Z directions. I'm using Fast 8 and the latest version of MoorDyn.
This is my input file:

--------------------- MoorDyn Input File ------------------------------------
Mooring system of the DTU Scaled 10MW Reference Wind Turbine installed on USTUTT INNWIND Triple Spar floater, v0.01, Mohammad Vahid Dastjerdi (m_vahid1989@yahoo.com)
FALSE Echo - echo the input file data (flag)
----------------------- LINE TYPES ------------------------------------------
1 NTypes - number of LineTypes
Name Diam MassDen EA BA/-zeta Can Cat Cdn Cdt
(-) (m) (kg/m) (N) (N-s/-) (-) (-) (-) (-)
main 0.0051679 0.165 1.13E6 -1.0 0.8 0.0 2.0 0.1
---------------------- CONNECTION PROPERTIES --------------------------------
6 NConnects - number of connections including fixeds and vessels
Node Type X Y Z M V FX FY FZ CdA CA
(-) (-) (m) (m) (m) (kg) (m^3) (kN) (kN) (kN) (m^2) (-)
1 fixed 10 0.0 -3.0 0 0 0 0 0 0 0
2 fixed -5.0 8.67 -3.0 0 0 0 0 0 0 0
3 fixed -5.0 -8.67 -3.0 0 0 0 0 0 0 0
4 vessel 0.555 0.0 0.345 0 0 0 0 0 0 0
5 vessel -0.2775 1.481 0.345 0 0 0 0 0 0 0
6 vessel -0.2775 -1.481 0.345 0 0 0 0 0 0 0
---------------------- LINE PROPERTIES --------------------------------------
3 NLines - number of line objects
Line LineType UnstrLen NumSegs NodeAnch NodeFair Flags/Outputs
(-) (-) (m) (-) (-) (-) (-)
1 main 10.167 10 1 4 -
2 main 10.167 10 2 5 -
3 main 10.167 10 3 6 -
---------------------- SOLVER OPTIONS ---------------------------------------
0.0001 dtM - time step to use in mooring integration (s)
9.80665 g -gravitational constant (m/s^2)
998.2 rhoW -water density (kg/m^3)
8.0e4 kbot - bottom stiffness (Pa/m)
8.0e3 cbot - bottom damping (Pa-s/m)
0.25 dtIC - time interval for analyzing convergence during IC gen (s)
300.0 TmaxIC - max time for ic gen (s)
4.0 CdScaleIC - factor by which to scale drag coefficients during dynamic relaxation (-)
0.001 threshIC - threshold for IC convergence (-)
------------------------ OUTPUTS --------------------------------------------
FairTen1
FairTen2
FairTen3
AnchTen1
AnchTen2
AnchTen3
L1N1fX1
END
------------------------- need this line --------------------------------------

but for L1N1fx1 (for outputting the fx on the fixed point of the line one for example) I'm getting zero values over the whole simulation time.
Also for other outputs I'm getting much higher values than expected.

Time FAIRTEN1 FAIRTEN2 FAIRTEN3 ANCHTEN1 ANCHTEN2 ANCHTEN3 Invalid
(s) (N) (N) (N) (N) (N) (N) -
0.0000 0.1580E+02 0.2741E+02 0.2741E+02 0.1138E+02 0.2297E+02 0.2297E+02 0.0000E+00
0.0250 0.2878E+02 0.1986E+02 0.1986E+02 0.1136E+02 0.2297E+02 0.2297E+02 0.0000E+00

Could you please help me on this?

Best regards
Masih


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