Dear jason,
Based on your suggestion, I have set NumCrctn = 1. However, it doesn’t work yet, still giving the error as shown below.
Running ROSCO-v2.5.0
A wind turbine controller framework for public use in the scientific field
Developed in collaboration: National Renewable Energy Laboratory
** Delft University of Technology, The Netherlands**
------------------------------------------------------------------------------
FAST_Solution:FAST_AdvanceStates:SrvD_UpdateStates:DLL_controller_call:BladedInterface option was
designed for an explicit-loose coupling scheme. Using last calculated values from DLL on all
subsequent calls until time is advanced. Warning will not be displayed again.
FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption1:FullOpt1_InputOutputSolve:SD_CalcOutput:
Small angle assumption violated in SUBROUTINE SmllRotTrans() due to a large UR_bar input angles.
The solution may be inaccurate. Simulation continuing, but future warnings from SmllRotTrans()
will be suppressed.
** Additional debugging message from SUBROUTINE SmllRotTrans():**
The BEM solution is being turned off due to low TSR. (TSR = -2.8106). This warning will not be
repeated though the condition may persist. (See GeomPhi output channel.)
FAST_Solution:FAST_AdvanceStates:AD_UpdateStates:BEMT_UpdateStates:UpdatePhi(node 22, blade
3):BEMT_UnCoupledSolve:There is no valid value of phi for these operating conditions: Vx = 2.461,
Vy = -309.29, rlocal = 54.04, theta = 4.79724E-02, geometric phi = 3.1336. This warning will not
be repeated though the condition may persist. (See GeomPhi output channel.)
FAST_Solution:FAST_AdvanceStates:ED_ABM4:ED_CalcContStateDeriv:SetCoordSy:Small angle assumption
violated in SUBROUTINE SmllRotTrans() due to a large platform displacement (ElastoDyn
SetCoordSy). The solution may be inaccurate. Simulation continuing, but future warnings from
SmllRotTrans() will be suppressed.
** Additional debugging message from SUBROUTINE SmllRotTrans(): 1.176 s**
FAST_AdvanceStates:AD_UpdateStates:BEMT_UpdateStates(node 11, blade
1):UA_UpdateStates:UA_UpdateDiscOtherState:ComputeKelvinChain:Mach number exceeds 1.0. Equations
cannot be evaluated.
** OpenFAST encountered an error at simulation time 1.175 of 300 seconds.**
** Simulation error level: FATAL ERROR**
** Aborting OpenFAST.**
Besides, I also set DT_UJac=1.5 as you suggested in https://forums.nrel.gov/t/modelling-marine-growth-on-5mw-oc3-hywind-spar-errors/2515/5, and it also doesn’t work.
Due to the adjustments of the simulation files, I repost the new link to share the files:https://drive.google.com/drive/folders/1mWF-Qjl2tnByCGWhRjwkatCLAgwot5Vq?usp=sharing. hoping you could give me some suggestion.
Best regards,