NREL 5MW Baseline Offshore Monopile Simulation

Provide feedback, request enhancements, and get help with wind-turbine computer-aided engineering tools.

Moderators: Bonnie.Jonkman, Jason.Jonkman

Eduardo.Melo
Posts: 2
Joined: Tue Jun 04, 2019 1:02 pm
Organization: Universidade Federal do Rio de Janeiro
Location: Rio de Janeiro - Brazil

NREL 5MW Baseline Offshore Monopile Simulation

Postby Eduardo.Melo » Wed Jun 05, 2019 8:52 am

Dear Jason


I keep receiving the same error everytime I try to run FAST with InflowWind entry.

First, I tested with steady wind, it ran normally. Then I introduced the InflowWind input, when I started to get the following messages:


FAST_Solution:FAST_AdvanceStates:ED_ABM4:ED_CalcContStateDeriv:SetCoordSy:Small angle assumption
violated in SUBROUTINE SmllRotTrans() due to a large tower deflection (ElastoDyn SetCoordSy). The
solution may be inaccurate. Simulation continuing, but future warnings from SmllRotTrans() will
be suppressed.
Additional debugging message from SUBROUTINE SmllRotTrans(): 0.3875 s

WARNING: High VT velocity encountered during induction factor calculation.
Blade number 1, Element number 1
VNW = 8.9453, VT = -560.63
WARNING: High VT velocity encountered during induction factor calculation.
Blade number 1, Element number 2
VNW = 10.169, VT = -557.62
WARNING: High VT velocity encountered during induction factor calculation.
Blade number 1, Element number 3
VNW = 10.322, VT = -554.83
WARNING: High VT velocity encountered during induction factor calculation.
Blade number 1, Element number 4
VNW = 10.305, VT = -551.68
WARNING: High VT velocity encountered during induction factor calculation.
Blade number 1, Element number 5
VNW = 10.293, VT = -548.55
WARNING: Induced velocity warning written 5 times. The message will not be repeated, though
the condition may persist.

FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFRC:BeddoesModel:ATT
ACH: Blade #1 element #4 is supersonic! Other elements are likely supersonic as well. Supersonic
mach nos. will be set to 0.7 to attempt continuation.
AD14_CalcOutput:ELEMFRC:BeddoesModel:SEPAR: Angle of attack = 2.64230E+20 is outside table.
CalcOutputs_And_SolveForInputs:SolveOption1:ED_SD_HD_BD_Orca_InputOutputSolve:HydroDyn_CalcOutput:
Angles in GetSmllRotAngs() are larger than 0.4 radians.
ED_SD_HD_BD_Orca_InputOutputSolve:HydroDyn_CalcOutput: Angles in GetSmllRotAngs() are larger than
0.4 radians.

FAST encountered an error at simulation time 0.3875 of 299.99 seconds.
Simulation error level: FATAL ERROR

Aborting FAST.


I am using NREL 5MW Baseline Offshore Monopile OC3 inputs.

What did I missed?


Thanks!

Jason.Jonkman
Posts: 4111
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: NREL 5MW Baseline Offshore Monopile Simulation

Postby Jason.Jonkman » Wed Jun 05, 2019 8:16 pm

Dear Eduardo,

I'm not sure what you mean when you say that you "introduced the InflowWind input"; do you mean that you used turbulent wind data from TurbSim?

It looks like your model is going unstable for some reason. I'm assuming you are using Test19 from the FAST v8.16 CertTest. Did you change this model in some way e.g. the time step sizes or geometry/mass/stiffness? Have you set proper initial conditions in terms of rotor speed and blade-pitch angle based on the mean wind speed you are simulating?

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Eduardo.Melo
Posts: 2
Joined: Tue Jun 04, 2019 1:02 pm
Organization: Universidade Federal do Rio de Janeiro
Location: Rio de Janeiro - Brazil

Re: NREL 5MW Baseline Offshore Monopile Simulation

Postby Eduardo.Melo » Mon Jun 24, 2019 9:37 am

Dear Jason

Sorry for the delayed response.

I was using a modified input file. When I changed to Test19 as input, it worked normally. After, I modified some parameters on Test19 to work with the Turbsim output that I have generated, and I had no more errors.

Now, I am trying to add output channels, but, I am getting an INVALID message on .SUM log.

Col Parameter Units
---- --------- -----
0 Time (s)
1 RtAeroFxh (N)
2 RtAeroFyh (N)
3 RtAeroFzh (N)
4 TwN1VUndx INVALID
5 RtAeroMxh (N·m)
6 RtAeroMyh (N·m)
7 RtAeroMzh (N·m)

This happens on ElastoDyn, AeroDyn, and every other module I try to add output channels.
Do you have any tip to make this work

Thanks!!

Jason.Jonkman
Posts: 4111
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: NREL 5MW Baseline Offshore Monopile Simulation

Postby Jason.Jonkman » Mon Jun 24, 2019 9:46 am

Dear Eduardo,

I can't speak to other output-related errors, but in your example from AeroDyn, I could foresee that you would get an invalid error for output TwN1VUndx if NTwOuts is not set to 1 or greater. What do you have NTwOuts set to in the primary AeroDyn input file?

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov


Return to “Computer-Aided Engineering Software Tools”

Who is online

Users browsing this forum: No registered users and 1 guest