Variable CompAA was not found

Wind & Water Computer-Aided Engineering Software Tools
1

Greetings,

I’m trying to run the 5MW_TLP_DLL_WTurb_WavesIrr_WavesMulti case and I am running into some problems. To begin with, I have not modificed the AeroDynv15 file, but on execution I get this error message:

Running AeroDyn.

FAST_InitializeAll:AD_Init:ParsePrimaryFileInfo:ParseLoVar:
 >> A fatal error occurred when parsing data from ".\NRELOffshrBsline5MW_Onshore_AeroDyn15.dat".
 >> The variable "CompAA" was not found on line #13.

I get this error for most of the 5MW NREL r-test files, unless I change the CompAero variable to 0.

I attach the AeroDyn file code underneath (eventhough it’s the default code).

Thanks a lot!

------- AERODYN v15 for OpenFAST INPUT FILE -----------------------------------------------
NREL 5.0 MW offshore baseline aerodynamic input properties.
======  General Options  ============================================================================
False         Echo               - Echo the input to "<rootname>.AD.ech"?  (flag)
"default"     DTAero             - Time interval for aerodynamic calculations {or "default"} (s)
          1   WakeMod            - Type of wake/induction model (switch) {0=none, 1=BEMT, 2=DBEMT, 3=OLAF} [WakeMod cannot be 2 or 3 when linearizing]
          2   AFAeroMod          - Type of blade airfoil aerodynamics model (switch) {1=steady model, 2=Beddoes-Leishman unsteady model} [AFAeroMod must be 1 when linearizing]
          1   TwrPotent          - Type tower influence on wind based on potential flow around the tower (switch) {0=none, 1=baseline potential flow, 2=potential flow with Bak correction}
          0   TwrShadow          - Calculate tower influence on wind based on downstream tower shadow (switch) {0=none, 1=Powles model, 2=Eames model}
True          TwrAero            - Calculate tower aerodynamic loads? (flag)
False         FrozenWake         - Assume frozen wake during linearization? (flag) [used only when WakeMod=1 and when linearizing]
False         CavitCheck         - Perform cavitation check? (flag) [AFAeroMod must be 1 when CavitCheck=true]
False         Buoyancy           - Include buoyancy effects? (flag)
False         CompAA             - Flag to compute AeroAcoustics calculation [used only when WakeMod = 1 or 2]
"unused"      AA_InputFile       - AeroAcoustics input file [used only when CompAA=true]
======  Environmental Conditions  ===================================================================
"default"     AirDens            - Air density (kg/m^3)
"default"     KinVisc            - Kinematic viscosity of working fluid (m^2/s)
"default"     SpdSound           - Speed of sound in working fluid (m/s)
"default"     Patm               - Atmospheric pressure (Pa) [used only when CavitCheck=True]
"default"     Pvap               - Vapour pressure of working fluid (Pa) [used only when CavitCheck=True]
======  Blade-Element/Momentum Theory Options  ====================================================== [unused when WakeMod=0 or 3]
          2   SkewMod            - Type of skewed-wake correction model (switch) {1=uncoupled, 2=Pitt/Peters, 3=coupled} [unused when WakeMod=0 or 3]
"default"     SkewModFactor      - Constant used in Pitt/Peters skewed wake model {or "default" is 15/32*pi} (-) [used only when SkewMod=2; unused when WakeMod=0 or 3]
True          TipLoss            - Use the Prandtl tip-loss model? (flag) [unused when WakeMod=0 or 3]
True          HubLoss            - Use the Prandtl hub-loss model? (flag) [unused when WakeMod=0 or 3]
True          TanInd             - Include tangential induction in BEMT calculations? (flag) [unused when WakeMod=0 or 3]
False         AIDrag             - Include the drag term in the axial-induction calculation? (flag) [unused when WakeMod=0 or 3]
False         TIDrag             - Include the drag term in the tangential-induction calculation? (flag) [unused when WakeMod=0,3 or TanInd=FALSE]
"Default"     IndToler           - Convergence tolerance for BEMT nonlinear solve residual equation {or "default"} (-) [unused when WakeMod=0 or 3]
        100   MaxIter            - Maximum number of iteration steps (-) [unused when WakeMod=0]
======  Dynamic Blade-Element/Momentum Theory Options  ============================================== [used only when WakeMod=2]
          2   DBEMT_Mod          - Type of dynamic BEMT (DBEMT) model {1=constant tau1, 2=time-dependent tau1, 3=constant tau1 with continuous formulation} (-) [used only when WakeMod=2]
          4   tau1_const         - Time constant for DBEMT (s) [used only when WakeMod=2 and DBEMT_Mod=1 or 3]
======  OLAF -- cOnvecting LAgrangian Filaments (Free Vortex Wake) Theory Options  ================== [used only when WakeMod=3]
"unused"      OLAFInputFileName  - Input file for OLAF [used only when WakeMod=3]
======  Beddoes-Leishman Unsteady Airfoil Aerodynamics Options  ===================================== [used only when AFAeroMod=2]
          3   UAMod              - Unsteady Aero Model Switch (switch) {2=B-L Gonzalez, 3=B-L Minnema/Pierce, 4=B-L HGM 4-states, 5=B-L 5 states, 6=Oye, 7=Boeing-Vertol} [used only when AFAeroMod=2]
True          FLookup            - Flag to indicate whether a lookup for f' will be calculated (TRUE) or whether best-fit exponential equations will be used (FALSE); if FALSE S1-S4 must be provided in airfoil input files (flag) [used only when AFAeroMod=2]
======  Airfoil Information =========================================================================
          1   AFTabMod           - Interpolation method for multiple airfoil tables {1=1D interpolation on AoA (first table only); 2=2D interpolation on AoA and Re; 3=2D interpolation on AoA and UserProp} (-)
          1   InCol_Alfa         - The column in the airfoil tables that contains the angle of attack (-)
          2   InCol_Cl           - The column in the airfoil tables that contains the lift coefficient (-)
          3   InCol_Cd           - The column in the airfoil tables that contains the drag coefficient (-)
          4   InCol_Cm           - The column in the airfoil tables that contains the pitching-moment coefficient; use zero if there is no Cm column (-)
          0   InCol_Cpmin        - The column in the airfoil tables that contains the Cpmin coefficient; use zero if there is no Cpmin column (-)
          8   NumAFfiles         - Number of airfoil files used (-)
"../5MW_Baseline/Airfoils/Cylinder1.dat"    AFNames            - Airfoil file names (NumAFfiles lines) (quoted strings)
"../5MW_Baseline/Airfoils/Cylinder2.dat"
"../5MW_Baseline/Airfoils/DU40_A17.dat"
"../5MW_Baseline/Airfoils/DU35_A17.dat"
"../5MW_Baseline/Airfoils/DU30_A17.dat"
"../5MW_Baseline/Airfoils/DU25_A17.dat"
"../5MW_Baseline/Airfoils/DU21_A17.dat"
"../5MW_Baseline/Airfoils/NACA64_A17.dat"
======  Rotor/Blade Properties  =====================================================================
True          UseBlCm            - Include aerodynamic pitching moment in calculations?  (flag)
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(1)        - Name of file containing distributed aerodynamic properties for Blade #1 (-)
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(2)        - Name of file containing distributed aerodynamic properties for Blade #2 (-) [unused if NumBl < 2]
"../5MW_Baseline/NRELOffshrBsline5MW_AeroDyn_blade.dat"    ADBlFile(3)        - Name of file containing distributed aerodynamic properties for Blade #3 (-) [unused if NumBl < 3]
======  Hub Properties ============================================================================== [used only when Buoyancy=True]
0.0   VolHub             - Hub volume (m^3)
0.0   HubCenBx           - Hub center of buoyancy x direction offset (m)
======  Nacelle Properties ========================================================================== [used only when Buoyancy=True]
0.0   VolNac             - Nacelle volume (m^3)
0,0,0 NacCenB            - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)
======  Tail fin Aerodynamics ======================================================================== 
False         TFinAero           - Calculate tail fin aerodynamics model (flag)
"unused"      TFinFile           - Input file for tail fin aerodynamics [used only when TFinAero=True]
======  Tower Influence and Aerodynamics ============================================================ [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
         12   NumTwrNds         - Number of tower nodes used in the analysis  (-) [used only when TwrPotent/=0, TwrShadow/=0, TwrAero=True, or Buoyancy=True]
TwrElev        TwrDiam        TwrCd          TwrTI          TwrCb !TwrTI used only with TwrShadow=2, TwrCb used only with Buoyancy=True
(m)              (m)           (-)            (-)           (-)
0.0000000E+00  6.0000000E+00  1.0000000E+00  1.0000000E-01  0.0
8.5261000E+00  5.7870000E+00  1.0000000E+00  1.0000000E-01  0.0
1.7053000E+01  5.5740000E+00  1.0000000E+00  1.0000000E-01  0.0
2.5579000E+01  5.3610000E+00  1.0000000E+00  1.0000000E-01  0.0
3.4105000E+01  5.1480000E+00  1.0000000E+00  1.0000000E-01  0.0
4.2633000E+01  4.9350000E+00  1.0000000E+00  1.0000000E-01  0.0
5.1158000E+01  4.7220000E+00  1.0000000E+00  1.0000000E-01  0.0
5.9685000E+01  4.5090000E+00  1.0000000E+00  1.0000000E-01  0.0
6.8211000E+01  4.2960000E+00  1.0000000E+00  1.0000000E-01  0.0
7.6738000E+01  4.0830000E+00  1.0000000E+00  1.0000000E-01  0.0
8.5268000E+01  3.8700000E+00  1.0000000E+00  1.0000000E-01  0.0
8.7600000E+01  3.8700000E+00  1.0000000E+00  1.0000000E-01  0.0
======  Outputs  ====================================================================================
True          SumPrint            - Generate a summary file listing input options and interpolated properties to "<rootname>.AD.sum"?  (flag)
          0   NBlOuts             - Number of blade node outputs [0 - 9] (-)
          1,          9,         19    BlOutNd             - Blade nodes whose values will be output  (-)
          0   NTwOuts             - Number of tower node outputs [0 - 9]  (-)
          1,          2,          6    TwOutNd             - Tower nodes whose values will be output  (-)
                   OutList             - The next line(s) contains a list of output parameters.  See OutListParameters.xlsx for a listing of available output channels, (-)
END of input file (the word "END" must appear in the first 3 columns of this last OutList line)
---------------------------------------------------------------------------------------
2

Dear @Pere.Palacin,

Are you by chance using OpenFAST input files that are incompatible with the version of OpenFAST you are simulating? The input file changes with each release of OpenFAST are documented here: 4.4. API changes between versions — OpenFAST v2.4.0 documentation.

As with any input file processing error, I would enable the Echo option to debug errors in input file formatting.

Best regards,

1 Like
3

Thanks a lot for your reply @Jason.Jonkman,

As far as I know I’m using the latest version of the OpebFAST input files. I just downloaded the files from this link: https://github.com/OpenFAST/r-test/releases/tag/v3.4.1 but I still get the same error.

I switched the echo parameter to True but it didn’t give me any more information regarding the error.

I checked the link that you have provided me but I don’t know how I can put the CompAA variable in the #13 line of code, without removing something else.

Thanks!

4

Dear @Pere.Palacin,

When comparing your AeroDyn input file and Echo file generated, what do you see? Is each line being read correctly up until the error is triggered?

Best regards,

1 Like
5

Dear @Jason.Jonkman,

Yes I believe it does. Here you can see the Echo file:

AD:

Echo file for AeroDyn 15 primary input file: .\NRELOffshrBsline5MW_Onshore_AeroDyn15.dat
------- AERODYN v15 for OpenFAST INPUT FILE -----------------------------------------------                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
NREL 5.0 MW offshore baseline aerodynamic input properties.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
======  General Options  ============================================================================                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
 True            = Echo                
 default         = DTAero              
 1               = WakeMod             
 2               = AFAeroMod           
 1               = TwrPotent           
 0               = TwrShadow           
 True            = TwrAero             
 False           = FrozenWake          
 False           = CavitCheck

ECH file:


This file of echoed input was generated by OpenFAST on 05-Apr-2023 at 22:00:25.

Data from OpenFAST primary input file "5MW_TLP_DLL_WTurb_WavesIrr_WavesMulti.fst":


               FTitle         - File Header: File Description (line 2)
  "FAST Certification Test #23: NREL 5.0 MW Baseline Wind Turbine with MIT-NREL TLP Configuration, for use in offshore analysis"

            T  Echo           - Echo input data to <RootName>.ech (flag)
               AbortLevel     - Error level when simulation should abort (string)
  "FATAL"
   6.0000E+01  TMax           - Total run time (s)
   1.2500E-02  DT             - Recommended module time step (s)
            2  InterpOrder    - Interpolation order for inputs and outputs {0=nearest neighbor ,1=linear, 2=quadratic} (-)
            0  NumCrctn       - Number of corrections{0=explicit calculation, i.e., no corrections} (-)
   9.9999E+04  DT_UJac        - Time between calls to get Jacobians (s)
   1.0000E+06  UJacSclFact    - Scaling factor used in Jacobians (-)

            1  CompElast      - Compute structural dynamics (switch) {1=ElastoDyn; 2=ElastoDyn + BeamDyn for blades}
            1  CompInflow     - inflow wind velocities (switch) {0=still air; 1=InflowWind}
            2  CompAero       - Compute aerodynamic loads (switch) {0=None; 1=AeroDyn}
            1  CompServo      - Compute control and electrical-drive dynamics (switch) {0=None; 1=ServoDyn}
            1  CompHydro      - Compute hydrodynamic loads (switch) {0=None; 1=HydroDyn}
            0  CompSub        - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn}
            1  CompMooring    - Compute mooring system (switch) {0=None; 1=MAP; 2=FEAMooring; 3=MoorDyn; 4=OrcaFlex}
            0  CompIce        - Compute ice loads (switch) {0=None; 1=IceFloe}
            0  MHK            - MHK turbine type (switch) {0=Not an MHK turbine; 1=Fixed MHK turbine; 2=Floating MHK turbine}

   9.8067E+00  Gravity        - Gravitational acceleration (m/s^2)
   1.2250E+00  AirDens        - Air density (kg/m^3)
   1.0250E+03  WtrDens        - Water density (kg/m^3)
   1.4640E-05  KinVisc        - Kinematic viscosity of working fluid (m^2/s)
   3.3500E+02  SpdSound       - Speed of sound in working fluid (m/s)
   1.0350E+05  Patm           - Atmospheric pressure (Pa)
   1.7000E+03  Pvap           - Vapour pressure of working fluid (Pa)
   2.0000E+02  WtrDpth        - Water depth (m)
   0.0000E+00  MSL2SWL        - Offset between still-water level and mean sea level (m)

               EDFile         - Name of file containing ElastoDyn input parameters (-)
  "NRELOffshrBsline5MW_MIT_NREL_TLP_ElastoDyn.dat"
               BDBldFile(1)   - Name of file containing BeamDyn blade 1input parameters (-)
  "../5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat"
               BDBldFile(2)   - Name of file containing BeamDyn blade 2input parameters (-)
  "../5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat"
               BDBldFile(3)   - Name of file containing BeamDyn blade 3input parameters (-)
  "../5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat"
               InflowFile     - Name of file containing inflow wind input parameters (-)
  "../5MW_Baseline/NRELOffshrBsline5MW_InflowWind_12mps.dat"
               AeroFile       - Name of file containing aerodynamic input parameters (-)
  "NRELOffshrBsline5MW_Onshore_AeroDyn15.dat"
               ServoFile      - Name of file containing control and electrical-drive input parameters (-)
  "NRELOffshrBsline5MW_MIT_NREL_TLP_ServoDyn.dat"
               HydroFile      - Name of file containing hydrodynamic input parameters (-)
  "NRELOffshrBsline5MW_MIT_NREL_TLP_HydroDyn.dat"
               SubFile        - Name of file containing sub-structural input parameters (-)
  "unused"
               MooringFile    - Name of file containing mooring system input parameters (-)
  "NRELOffshrBsline5MW_MIT_NREL_TLP_MAP.dat"
               IceFile        - Name of file containing ice input parameters (-)
  "unused"

            T  SumPrint       - Print summary data to <RootName>.sum (flag)
   1.0000E+00  SttsTime       - Amount of time between screen status messages (s)
   1.0000E+03  ChkptTime      - Amount of time between creating checkpoint files for potential restart (s)
               DT_Out         - Time step for tabular output (s)
  "0.0125"
   0.0000E+00  TStart         - Time to begin tabular output (s)
            0  OutFileFmt     - Format for tabular (time-marching) output file(s) {0: uncompressed binary and text file, 1: text file [<RootName>.out], 2: compressed binary file [<RootName>.outb], 3: both text and compressed binary, 4: uncompressed binary <RootName>.outb]; add for combinations) (-)
            T  TabDelim       - Use tab delimiters in text tabular output file? (flag)
               OutFmt         - Format used for text tabular output (except time).  Resulting field should be 10 characters. (-)
  "ES15.7E2"

            F  Linearize      - Linearization analysis (flag)
            F  CalcSteady     - Calculate a steady-state periodic operating point before linearization? (flag)
            3  TrimCase       - Controller parameter to be trimmed {1:yaw; 2:torque; 3:pitch} (-)
   1.0000E-03  TrimTol        - Tolerance for the rotational speed convergence (-)
   1.0000E-02  TrimGain       - Proportional gain for the rotational speed error (>0) (rad/(rad/s) for yaw or pitch; Nm/(rad/s) for torque)
   0.0000E+00  Twr_Kdmp       - Damping factor for the tower (N/(m/s))
   0.0000E+00  Bld_Kdmp       - Damping factor for the blades (N/(m/s))
            2  NLinTimes      - Number of times to linearize (-) [>=1]

            1  LinInputs      - Include inputs in linearization (switch) {0=none; 1=standard; 2=all module inputs (debug)}
            1  LinOutputs     - Include outputs in linearization (switch) (0=none; 1=from OutList(s); 2=all module outputs (debug))
            F  LinOutJac      - Include full Jacabians in linearization output (for debug) (flag)
            F  LinOutMod      - Write module-level linearization output files in addition to output for full system? (flag)

            0  WrVTK          - Write VTK visualization files (0=none; 1=initialization data only; 2=animation; 3=mode shapes)
            2  VTK_Type       - Type of  VTK visualization data: (1=surfaces; 2=basic meshes (lines/points); 3=all meshes)
            F  VTK_fields     - Write mesh fields to VTK data files? (flag)
   1.5000E+01  VTK_fps        - Frame rate for VTK output(fps)

Thanks!

6

Dear @Pere.Palacin,

Can you share the full message written to the Command Prompt when you execute OpenFAST?

Best regards,

1 Like
7

Here you have @Jason.Jonkman,

PS C:\Users\perep\openfast\reg_tests\r-test\glue-codes\openfast\5MW_TLP_DLL_WTurb_WavesIrr_WavesMulti> C:\Users\perep\openfast\openfast_x64.exe 5MW_TLP_DLL_WTurb_WavesIrr_WavesMulti.fst

**************************************************************************************************
OpenFAST

Copyright (C) 2022 National Renewable Energy Laboratory
Copyright (C) 2022 Envision Energy USA LTD

This program is licensed under Apache License Version 2.0 and comes with ABSOLUTELY NO WARRANTY.
See the "LICENSE" file distributed with this software for details.
**************************************************************************************************

OpenFAST-v3.3.0
Compile Info:
 - Compiler: Intel(R) Fortran Compiler 1900
 - Architecture: 64 bit
 - Precision: single
 - OpenMP: No
 - Date: Nov 02 2022
 - Time: 14:07:06
Execution Info:
 - Date: 04/05/2023
 - Time: 22:00:25+0200

OpenFAST input file heading:
    FAST Certification Test #23: NREL 5.0 MW Baseline Wind Turbine with MIT-NREL TLP
    Configuration, for use in offshore analysis

Running ElastoDyn.
Nodal outputs section of ElastoDyn input file not found or improperly formatted.
Running AeroDyn.

FAST_InitializeAll:AD_Init:ParsePrimaryFileInfo:ParseLoVar:
 >> A fatal error occurred when parsing data from ".\NRELOffshrBsline5MW_Onshore_AeroDyn15.dat".
 >> The variable "CompAA" was not found on line #13.

 OpenFAST encountered an error during module initialization.
 Simulation error level: FATAL ERROR

 Aborting OpenFAST.

I am using version 3.3.0 of OpenFAST and maybe I’m running input files form version 3.4.1, but I can’t find the rtest files for the version 3.3.0 on Github…

Thanks

8

Dear @Pere.Palacin,

Yes, that is the problem–you are running the OpenFAST v3.3 executable while using input files formatted for OpenFAST v3.4.1. The Buoyancy input and related inputs exist in the AeroDyn input file of OpenFAST v3.4.1, which OpenFAST v3.3 would not understand.

I’m not sure why the v3.3 release of the OpenFAST r-test was not given here: Releases · OpenFAST/r-test · GitHub, but nevertheless, the release is tagged in the r-test repository, which you can access via GitHub (GitHub - OpenFAST/r-test at v3.3.0).

Alternatively, you can upgrade and run OpenFAST v3.4.1.

Best regards,

1 Like
9

Thanks a lot @Jason.Jonkman, that was indeed the problem. I managed to run the r-test code without any problem using the 3.3.0 version. Thanks again.

Now I wanted to ask you if you knew how I could tweak the TLP paramaters of the file. For instance, I want to change the lenght of the cables, making the platform shorter but upon execution I get this error message:

MAP++ environment properties (set externally)...
    Gravity constant          [m/s^2]  : 9.81
    Sea density               [kg/m^3] : 1025.00
    Water depth               [m]      : 200.00
    Vessel reference position [m]      : 0.00 , 0.00 , 0.00
Intialization: MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. LMax = 184.998473 [m].
MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. Line segment 1.
MAP_FATAL[88] : Line failed.
MAP_FATAL[39] : Could not run the first solve. Solver option (INNER_FTOL, INNER_GTOL, INNER_XTOL, INNER_MAX_ITS) could be inadvertendly set to a negative value or line geometry/line cable library is not properly defined.
MAP_ERROR[7] : Failed to write node information to the MAP summary file.
MAP_FATAL[37] : Failed to write the MAP summary file.



FAST_InitializeAll:HydroDyn_Init:Waves_Init:VariousWaves_Init:Changed WaveNDir from 13 to 15 so
that an equal number of frequencies are assigned to each direction.
FAST_InitializeAll:MAP_Init:MAP_FATAL[59] : Approached a geometric limitation that the MSQS model
is unable to solve. LMax = 184.998473 [m].
MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. Line
segment 1.
MAP_FATAL[88] : Line failed.
MAP_FATAL[39] : Could not run the first solve. Solver option (INNER_FTOL, INNER_GTOL, INNER_XTOL,
INNER_MAX_ITS) could be inadvertendly set to a negative value or line geometry/line cable library
is not properly defined.
MAP_ERROR[7] : Failed to write node information to the MAP summary file.
MAP_FATAL[37] : Failed to write the MAP summary file.


 OpenFAST encountered an error during module initialization.
 Simulation error level: FATAL ERROR

 Aborting OpenFAST.

The only changes I’ve done are on the bottom of the SPAR from: -47,89 m to -15m on the MAP++ and the HydroDyn files. Also I’ve changed the TLP unstretched lenght to 185 m. I would really appreciate some guidance regarding this topic.

Thanks a lot,
Pere

MAP File:

---------------------- LINE DICTIONARY ---------------------------------------
LineType     Diam     MassDenInAir     EA        CB   CIntDamp  Ca   Cdn  Cdt
(-)          (m)      (kg/m)          (N)       (-)   (Pa-s)    (-)  (-)  (-)
Material     0.127    116.027         1.5E9     1.0    0        0    0    0
---------------------- NODE PROPERTIES ---------------------------------------
Node Type     X     Y     Z     M     B     FX   FY   FZ
(-)  (-)     (m)   (m)   (m)   (kg)  (mˆ3)  (N)  (N)  (N)
1    fix      27   0    depth   0     0      #    #    #
2    Vessel   27   0   -15   0     0      #    #    #
---------------------- LINE PROPERTIES ---------------------------------------
Line  LineType  UnstrLen    NodeAnch  NodeFair  Flags
(-)      (-)       (m)         (-)       (-)       (-)
1       Material   185       1         2         tension_anch tension_fair
---------------------- SOLVER OPTIONS-----------------------------------------
Option
(-)
repeat 270 180 90 0 270 180 90
10

Dear @Pere.Palacin,

From the error, it looks like your setting of unstretched length in MAP++ (UnstrLen) is too large such that MAP++ cannot find a solution to the catenary equations. For a water depth of 200 m and a fairlead draft of 15 m, you’d want the stretched length of the cable (include the effects of pretension) to be 185 m to ensure zero heave displacement, which means UnstrLen must be less than 185 m.

Best regards,

1 Like
11

Dear @Jason.Jonkman,

Thanks a lot for your reply. Sadly, I have already tried reducing the UnstrLen parameter. Even setting values as low as 150 m yields the same results:

FAST_Solution:FAST_AdvanceStates:ED_ABM4:ED_CalcContStateDeriv:SetCoordSy:Small angle assumption
violated in SUBROUTINE SmllRotTrans() due to a large blade deflection (ElastoDyn SetCoordSy). The
solution may be inaccurate. Simulation continuing, but future warnings from SmllRotTrans() will
be suppressed.
 Additional debugging message from SUBROUTINE SmllRotTrans(): 0.3 s
interval 46 Update_state: MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. LMax = 149.714541 [m].
MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. Line segment 1.
MAP_FATAL[88] : Line failed.



FAST_Solution:FAST_AdvanceStates:MAP_UpdateStates:MAP_FATAL[59] : Approached a geometric
limitation that the MSQS model is unable to solve. LMax = 149.714541 [m].
MAP_FATAL[59] : Approached a geometric limitation that the MSQS model is unable to solve. Line
segment 1.
MAP_FATAL[88] : Line failed.

Best regards

12

Dear @Pere.Palacin,

My guess is that a tendon is going slack during the transient dynamic time-domain simulation.

MAP++ cannot solve the situation where a near-vertical tendon goes slack because the catenary equations do not have a unique solution under such conditions. You’ll have to either design the system so that the tendons don’t go slack or switch to a different mooring module (such as MoorDyn) that supports the simulation of slack tendon conditions.

Best regards,

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13

Thanks a lot! I managed to get the MoorDyn file running.

Have a nice day!

1 Like