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Clump weight in Moordyn

Posted: Sun Oct 13, 2019 7:08 pm
by Krishnaveni.Balakrishnan
Dear Dr.Jonkman

Greetings for the day!Thank you for your responses before. I just have quick question in Moordyn for OC3 Hywind model. I would like to add a clump weight at about 0.1L of the mooring line.Say if my mooring line length is 902 this is going to be approximately about 90m from fairlead. I have created 'Connect' which are described as intermediate points in all the three lines . Below is the moordyn file I have used.But am ending up with error message,I know there is a mistake in introducing the new connections for clump weight.I request you to kindly help me in catching it.

Thanks
Krishnaveni




--------------------- MoorDyn Input File ------------------------------------
MoorDyn input file of the mooring system for OC3-Hywind
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 0.09 77.7066 384.243E6 -0.8 1.0 0.0 1.6 0.1
---------------------- CONNECTION PROPERTIES --------------------------------
6 NConnects - number of connections including anchors and fairleads
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 853.87 0.0 -320.0 0 0 0 0 0 0 0
2 fixed -426.94 739.47 -320.0 0 0 0 0 0 0 0
3 fixed -426.94 -739.47 -320.0 0 0 0 0 0 0 0
4 vessel 5.2 0.0 -70.0 0 0 0 0 0 0 0
5 vessel -2.6 4.5 -70.0 0 0 0 0 0 0 0
6 vessel -2.6 -4.5 -70.0 0 0 0 0 0 0 0
7 connect 45 77.9 -115 0 0 0 0 0 0 0
8 connect -90 0 -115 0 0 0 0 0 0 0
9 connect 45 -77.9 -115 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 902.2 20 1 4 p
2 main 902.2 20 2 5 -
3 main 902.2 20 3 6 -
---------------------- SOLVER OPTIONS ---------------------------------------
0.001 dtM - time step to use in mooring integration (s)
3.0e6 kBot - bottom stiffness (Pa/m)
3.0e5 cBot - bottom damping (Pa-s/m)
320 WtrDpth - water depth (m)
1.0 dtIC - time interval for analyzing convergence during IC gen (s)
60.0 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
AnchTen3
L2N4pX
END
------------------------- need this line --------------------------------------

Re: Clump weight in Moordyn

Posted: Mon Oct 14, 2019 7:46 pm
by Jason.Jonkman
Dear Krishnaveni,

I see a couple problems with your MoorDyn input file:
1) You've define the properties of 9 connection nodes (fixed, vessel, connect), but you've set NConnects = 6 (instead of 9).
2) You've added connect nodes, but you didn't attach any lines to them. I would think you'd want to set NLInes = 3 and connect lines to the connect nodes.

I hope that helps.

Best regards,