Wec-Sim/Mooring Model Issue

Hi All,

I am trying to simulate the OC3 spar in WEC-SIM with the MoorDyn-C, and my code and model :

%% Body Data
body(1) = bodyClass(bodyFile);
body(1).geometryFile = 'geometry/Spar_OC3_mm.stl';
body(1).mass = 7.46633E+06; % 7.46633E+06
body(1).inertia = [4229230000 4229230000 164230000];

B_linear = zeros(6);
B_linear(1,1) = 1.0e5;  % Surge
B_linear(2,2) = 1.0e5;  % Sway
B_linear(3,3) = 1.3e5;  % Heave
B_linear(6,6) = 1.3e7;  % Yaw
body(1).linearDamping = B_linear;

%% PTO and Constraint Parameters
% Floating (6DOF) Joint
constraint(1) = constraintClass('Constraint1'); 
constraint(1).location = [0 0 0];     
                       
%% Mooring
% Moordyn
mooring(1) = mooringClass('mooring');       	             % Initialize mooringClass
mooring(1).moorDyn = 1;
mooring(1).moorDynLines = 3;                	             % Specify number of lines
mooring(1).moorDynNodes = [20 20 20];       	             % Specify number of nodes per line
mooring(1).location = [0.0 0.0 -70.0];

mooring(1).moorDynInputFile = 'Mooring/lines_v2.txt';        % Specify MoorDyn input file path"

and the “lines_v2.txt” is

--------------------- MoorDyn Input File ------------------------------------
Mooring system for OC3-Hywind
----------------------- LINE TYPES ------------------------------------------
Name     Diam      MassDen       EA    BA/-zeta    EI    Cd      Ca     CdAx   CaAx
(-)       (m)      (kg/m)        (N)    (N-s/-)    (-)   (-)     (-)    (-)    (-)
main     0.09      77.7066   384.243E6  -0.8       0.0   1.6     1.0    0.1    0.0
---------------------- POINTS --------------------------------
ID     Attachment  X        Y         Z      M      V    CdA   CA
(-)     (-)      (m)      (m)      (m)     (kg)  (m^3) (m^2)  (-)
1      fixed    853.87     0.0    -320.0    0     0      0     0
2      fixed   -426.94   739.47   -320.0    0     0      0     0
3      fixed   -426.94  -739.47   -320.0    0     0      0     0
4      vessel     5.2      0.0     -70.0    0     0      0     0
5      vessel    -2.6      4.5     -70.0    0     0      0     0
6      vessel    -2.6     -4.5     -70.0    0     0      0     0
---------------------- LINES --------------------------------------
ID      LineType   AttachA   AttachB  UnstrLen  NumSegs   Outputs
(-)       (-)        (-)       (-)       (m)       (-)      (-)
1         main       1         4        902.2      20        tp
2         main       2         5        902.2      20        tp
3         main       3         6        902.2      20        tp
---------------------- SOLVER OPTIONS ---------------------------------------
2             writeLog      Write a log file
rk4          tscheme       2nd order Runge-Kutta
0.0001         dtM           time step to use in mooring integration (s)
3.0e6         kBot          bottom stiffness (Pa/m)
3.0e5         cBot          bottom damping (Pa-s/m)
1025.0        WtrDnsty      water density (kg/m^3)
320           WtrDpth       water depth (m)
20.0           dtIC          time interval for analyzing convergence during IC gen (s)
100.0         TmaxIC        max time for ic gen (s)
3.0           CdScaleIC     factor by which to scale drag coefficients during dynamic relaxation (-)
0.0001         threshIC      threshold for IC convergence (-)
1       disableOutTime
------------------------ OUTPUTS --------------------------------------------
FairTen1
FairTen2
FairTen3
AnchTen1
AnchTen2
AnchTen3
------------------------- need this line --------------------------------------

But, every time I ran the Simulink, the mooring line initialization would give the wrong coordinates of coupled points 4, 5, and 6. Then, if I run the simulation, MATLAB crashed and gave the following crash report. But when I try the same “lines_v2.txt” in Python like @Ryan.Davies suggested, there are no errors.


Does anyone know how I could troubleshoot this? Any help is appreciated. Thanks in advance!

Best,
Chaozhi Qiu