Hello,
“This post is about the issue I have faced with huge blade and tower load oscillations”
I have a load case where the turbine is rigid, the drive train rotates freely without load as the generator is disabled and the gravitation is switched off. The pitch is fixed (zero) and the yaw is fixed 10 degrees. I have represented the yaw error as inflow wind with direction change of 10 degrees. The initial speed of the rotor is 8 rpm. The wind speed is variable from 0 to 10 m/s in 100 seconds. I have used the equilibrium inflow model and the tip and hub losses are switched on. The simulation results are quite strange as there are huge oscillations in the blade root forces and bending momets, particularly in blade Root_Mx. There are also similar oscillations in tower loads. I have also tried increaing the time step of the simulation time, but it did not work. What could be the reasons for it?
I have attached an image of the blade Root_Mx. The simulation time step is 0.02 and the simulation time is 300 seconds. As I have used the filtered data to plot the graph, the oscillations does seem to be periodic, but they are periodic in the actual case.
Thanks,
Chaitanya
Dear Chaitanya,
You have somewhat of an odd simulation set up and it would help to see other outputs to understand what is going on (like the rotor speed). My guess is that the rotor would accelerate up until a speed where the mean aerodynamic torque is zero. Once the rotor speed reaches a quasi-equilibrium, I would expect the mean blade-root Mx to be zero (like the mean torque). I would expect the blade-root bending moments to oscillate with the rotor frequency (and potentially its harmonics) because in skewed (yawed) flow, the blades move into and out of the flow. This is basically what you are seeing.
Best regards,
Hi Jason,
Tanks for your response. The information you have provided is very much useful to me. However, I could not figure it out the reason for such high amplitude of the oscillations. Moreover, The oscillations did not converge to zero after the rotor speed has reached quasi equilibrium state as you have said. I have attached the plot of the rotor speed.
Thanks,
Chaitanya
Dear Chaitanya,
Your plot of rotor speed confirms what I was saying–the rotor accelerates up until a speed where the mean aerodynamic torque is zero. Once the rotor speed is fixed, the mean aerodynamic torque and blade-root Mx are zero, but Mx oscillates because in skewed flow, the blade moves into and out of the flow.
Best regards,
hi jason
I have modeled a 5kw turbine in FAST software and got RootMxb1 and RootMyb1 results, but I don’t know why it oscilates so much, if possible, please give me some advice as to why this happens.
my code is here:
------- FAST INPUT FILE --------------------------------------------------------
FAST certification Test #15: FAST model of a SWRT 3-bladed upwind turbine. Note- SWRT rotates in CCW direction- some inputs will be mirror image of the actual turbine.
Model properties from “SWRTv1p2.adm” and SWRT “AdamsWT_MakeBladeDat_v12.xls”. JEM Jan., 2004. Updated by J. Jonkman, NREL, Feb, 2004. Compatible with FAST v7.02.00.
---------------------- SIMULATION CONTROL --------------------------------------
False Echo - Echo input data to “echo.out” (flag)
1 ADAMSPrep - ADAMS preprocessor mode {1: Run FAST, 2: use FAST as a preprocessor to create an ADAMS model, 3: do both} (switch)
1 AnalMode - Analysis mode {1: Run a time-marching simulation, 2: create a periodic linearized model} (switch)
3 NumBl - Number of blades (-)
650.0 TMax - Total run time (s)
0.005 DT - Integration time step (s)
---------------------- TURBINE CONTROL -----------------------------------------
0 YCMode - Yaw control mode {0: none, 1: user-defined from routine UserYawCont, 2: user-defined from Simulink/Labview} (switch)
0 TYCOn - Time to enable active yaw control (s) [unused when YCMode=0]
2 PCMode - Pitch control mode {0: none, 1: user-defined from routine PitchCntrl, 2: user-defined from Simulink/Labview} (switch)
0 TPCOn - Time to enable active pitch control (s) [unused when PCMode=0]
3 VSContrl - Variable-speed control mode {0: none, 1: simple VS, 2: user-defined from routine UserVSCont, 3: user-defined from Simulink/Labview} (switch)
260 VS_RtGnSp - Rated generator speed for simple variable-speed generator control (HSS side) (rpm) [used only when VSContrl=1]
211.08083 VS_RtTq - Rated generator torque/constant generator torque in Region 3 for simple variable-speed generator control (HSS side) (N-m) [used only when VSContrl=1]
0.0031225 VS_Rgn2K - Generator torque constant in Region 2 for simple variable-speed generator control (HSS side) (N-m/rpm^2) [used only when VSContrl=1]
0.0 VS_SlPc - Rated generator slip percentage in Region 2 1/2 for simple variable-speed generator control (%) [used only when VSContrl=1]
1 GenModel - Generator model {1: simple, 2: Thevenin, 3: user-defined from routine UserGen} (switch) [used only when VSContrl=0]
True GenTiStr - Method to start the generator {T: timed using TimGenOn, F: generator speed using SpdGenOn} (flag)
True GenTiStp - Method to stop the generator {T: timed using TimGenOf, F: when generator power = 0} (flag)
110 SpdGenOn - Generator speed to turn on the generator for a startup (HSS speed) (rpm) [used only when GenTiStr=False]
0.0 TimGenOn - Time to turn on the generator for a startup (s) [used only when GenTiStr=True]
9999.9 TimGenOf - Time to turn off the generator (s) [used only when GenTiStp=True]
1 HSSBrMode - HSS brake model {1: simple, 2: user-defined from routine UserHSSBr, 3: user-defined from Labview} (switch)
9999.9 THSSBrDp - Time to initiate deployment of the HSS brake (s)
9999.9 TiDynBrk - Time to initiate deployment of the dynamic generator brake [CURRENTLY IGNORED] (s)
9999.9 TTpBrDp(1) - Time to initiate deployment of tip brake 1 (s)
9999.9 TTpBrDp(2) - Time to initiate deployment of tip brake 2 (s)
9999.9 TTpBrDp(3) - Time to initiate deployment of tip brake 3 (s) [unused for 2 blades]
9999.9 TBDepISp(1) - Deployment-initiation speed for the tip brake on blade 1 (rpm)
9999.9 TBDepISp(2) - Deployment-initiation speed for the tip brake on blade 2 (rpm)
9999.9 TBDepISp(3) - Deployment-initiation speed for the tip brake on blade 3 (rpm) [unused for 2 blades]
9999.9 TYawManS - Time to start override yaw maneuver and end standard yaw control (s)
9999.9 TYawManE - Time at which override yaw maneuver reaches final yaw angle (s)
0.0 NacYawF - Final yaw angle for yaw maneuvers (degrees)
9999.9 TPitManS(1) - Time to start override pitch maneuver for blade 1 and end standard pitch control (s)
9999.9 TPitManS(2) - Time to start override pitch maneuver for blade 2 and end standard pitch control (s)
9999.9 TPitManS(3) - Time to start override pitch maneuver for blade 3 and end standard pitch control (s) [unused for 2 blades]
9999.9 TPitManE(1) - Time at which override pitch maneuver for blade 1 reaches final pitch (s)
9999.9 TPitManE(2) - Time at which override pitch maneuver for blade 2 reaches final pitch (s)
9999.9 TPitManE(3) - Time at which override pitch maneuver for blade 3 reaches final pitch (s) [unused for 2 blades]
0.0 BlPitch(1) - Blade 1 initial pitch (degrees)
0.0 BlPitch(2) - Blade 2 initial pitch (degrees)
0.0 BlPitch(3) - Blade 3 initial pitch (degrees) [unused for 2 blades]
0.0 BlPitchF(1) - Blade 1 final pitch for pitch maneuvers (degrees)
0.0 BlPitchF(2) - Blade 2 final pitch for pitch maneuvers (degrees)
0.0 BlPitchF(3) - Blade 3 final pitch for pitch maneuvers (degrees) [unused for 2 blades]
---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
9.80665 Gravity - Gravitational acceleration (m/s^2)
---------------------- FEATURE FLAGS -------------------------------------------
False FlapDOF1 - First flapwise blade mode DOF (flag)
False FlapDOF2 - Second flapwise blade mode DOF (flag)
False EdgeDOF - First edgewise blade mode DOF (flag)
False TeetDOF - Rotor-teeter DOF (flag) [unused for 3 blades]
False DrTrDOF - Drivetrain rotational-flexibility DOF (flag)
True GenDOF - Generator DOF (flag)
False YawDOF - Yaw DOF (flag)
False TwFADOF1 - First fore-aft tower bending-mode DOF (flag)
False TwFADOF2 - Second fore-aft tower bending-mode DOF (flag)
False TwSSDOF1 - First side-to-side tower bending-mode DOF (flag)
False TwSSDOF2 - Second side-to-side tower bending-mode DOF (flag)
True CompAero - Compute aerodynamic forces (flag)
False CompNoise - Compute aerodynamic noise (flag)
---------------------- INITIAL CONDITIONS --------------------------------------
0.0 OoPDefl - Initial out-of-plane blade-tip displacement (meters)
0.0 IPDefl - Initial in-plane blade-tip deflection (meters)
0.0 TeetDefl - Initial or fixed teeter angle (degrees) [unused for 3 blades]
0.0 Azimuth - Initial azimuth angle for blade 1 (degrees)
0.0 RotSpeed - Initial or fixed rotor speed (rpm)
0.0 NacYaw - Initial or fixed nacelle-yaw angle (degrees)
0.0 TTDspFA - Initial fore-aft tower-top displacement (meters)
0.0 TTDspSS - Initial side-to-side tower-top displacement (meters)
---------------------- TURBINE CONFIGURATION -----------------------------------
2.562 TipRad - The distance from the rotor apex to the blade tip (meters)
0.15 HubRad - The distance from the rotor apex to the blade root (meters)
1 PSpnElN - Number of the innermost blade element which is still part of the pitchable portion of the blade for partial-span pitch control [1 to BldNodes] [CURRENTLY IGNORED] (-)
0.0 UndSling - Undersling length [distance from teeter pin to the rotor apex] (meters) [unused for 3 blades]
-0.0145 HubCM - Distance from rotor apex to hub mass [positive downwind] (meters)
-0.479 OverHang - Distance from yaw axis to rotor apex [3 blades] or teeter pin [2 blades] (meters)
0.28 NacCMxn - Downwind distance from the tower-top to the nacelle CM (meters)
0.00 NacCMyn - Lateral distance from the tower-top to the nacelle CM (meters)
0.33 NacCMzn - Vertical distance from the tower-top to the nacelle CM (meters)
10.0 TowerHt - Height of tower above ground level [onshore] or MSL [offshore] (meters)
0.398 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (meters)
0.0 TwrRBHt - Tower rigid base height (meters)
-3.0 ShftTilt - Rotor shaft tilt angle (degrees). Negative for an upwind rotor.
0.0 Delta3 - Delta-3 angle for teetering rotors (degrees) [unused for 3 blades]
-5.0 PreCone(1) - Blade 1 cone angle (degrees)
-5.0 PreCone(2) - Blade 2 cone angle (degrees)
-5.0 PreCone(3) - Blade 3 cone angle (degrees) [unused for 2 blades]
0.0 AzimB1Up - Azimuth value to use for I/O when blade 1 points up (degrees)
---------------------- MASS AND INERTIA ----------------------------------------
1.75 YawBrMass - Yaw bearing mass (kg)
263.0 NacMass - Nacelle mass (kg)
51.5 HubMass - Hub mass (kg)
0.0 TipMass(1) - Tip-brake mass, blade 1 (kg)
0.0 TipMass(2) - Tip-brake mass, blade 2 (kg)
0.0 TipMass(3) - Tip-brake mass, blade 3 (kg) [unused for 2 blades]
20.62 NacYIner - Nacelle inertia about yaw axis (kg m^2)
0.5 GenIner - Generator inertia about HSS (kg m^2)
11 HubIner - Hub inertia about rotor axis [3 blades] or teeter axis [2 blades] (kg m^2)
---------------------- DRIVETRAIN ----------------------------------------------
100.0 GBoxEff - Gearbox efficiency (%)
87.0 GenEff - Generator efficiency [ignored by the Thevenin and user-defined generator models] (%)
1.0 GBRatio - Gearbox ratio (-)
False GBRevers - Gearbox reversal {T: if rotor and generator rotate in opposite directions} (flag)
6000 HSSBrTqF - Fully deployed HSS-brake torque (N-m)
0.0 HSSBrDT - Time for HSS-brake to reach full deployment once initiated (sec) [used only when HSSBrMode=1]
“unused” DynBrkFi - File containing a mech-gen-torque vs HSS-speed curve for a dynamic brake [CURRENTLY IGNORED] (quoted string)
5.0E6 DTTorSpr - Drivetrain torsional spring (N-m/rad)
1.0E5 DTTorDmp - Drivetrain torsional damper (N-m/(rad/s))
---------------------- SIMPLE INDUCTION GENERATOR ------------------------------
9999.9 SIG_SlPc - Rated generator slip percentage (%) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_SySp - Synchronous (zero-torque) generator speed (rpm) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_RtTq - Rated torque (N-m) [used only when VSContrl=0 and GenModel=1]
9999.9 SIG_PORt - Pull-out ratio (Tpullout/Trated) (-) [used only when VSContrl=0 and GenModel=1]
---------------------- THEVENIN-EQUIVALENT INDUCTION GENERATOR -----------------
9999.9 TEC_Freq - Line frequency [50 or 60] (Hz) [used only when VSContrl=0 and GenModel=2]
9998 TEC_NPol - Number of poles [even integer > 0] (-) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SRes - Stator resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RRes - Rotor resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_VLL - Line-to-line RMS voltage (volts) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SLR - Stator leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RLR - Rotor leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_MR - Magnetizing reactance (ohms) [used only when VSContrl=0 and GenModel=2]
---------------------- PLATFORM ------------------------------------------------
0 PtfmModel - Platform model {0: none, 1: onshore, 2: fixed bottom offshore, 3: floating offshore} (switch)
“unused” PtfmFile - Name of file containing platform properties (quoted string) [unused when PtfmModel=0]
---------------------- TOWER ---------------------------------------------------
40 TwrNodes - Number of tower nodes used for analysis (-)
“tower-SWRT-5KW.dat” TwrFile - Name of file containing tower properties (quoted string)
---------------------- NACELLE-YAW ---------------------------------------------
8.471E6 YawSpr - Nacelle-yaw spring constant (N-m/rad)
7930.0 YawDamp - Nacelle-yaw damping constant (N-m/(rad/s))
0.0 YawNeut - Neutral yaw position–yaw spring force is zero at this yaw (degrees)
---------------------- FURLING -------------------------------------------------
False Furling - Read in additional model properties for furling turbine (flag)
“unused” FurlFile - Name of file containing furling properties (quoted string) [unused when Furling=False]
---------------------- ROTOR-TEETER --------------------------------------------
0 TeetMod - Rotor-teeter spring/damper model {0: none, 1: standard, 2: user-defined from routine UserTeet} (switch) [unused for 3 blades]
0.0 TeetDmpP - Rotor-teeter damper position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetDmp - Rotor-teeter damping constant (N-m/(rad/s)) [used only for 2 blades and when TeetMod=1]
0.0 TeetCDmp - Rotor-teeter rate-independent Coulomb-damping moment (N-m) [used only for 2 blades and when TeetMod=1]
0.0 TeetSStP - Rotor-teeter soft-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetHStP - Rotor-teeter hard-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetSSSp - Rotor-teeter soft-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
0.0 TeetHSSp - Rotor-teeter hard-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
---------------------- TIP-BRAKE -----------------------------------------------
0.0 TBDrConN - Tip-brake drag constant during normal operation, CdArea (m^2)
0.0 TBDrConD - Tip-brake drag constant during fully-deployed operation, CdArea (m^2)
0.0 TpBrDT - Time for tip-brake to reach full deployment once released (sec)
---------------------- BLADE ---------------------------------------------------
“SWRT_Blade.dat” BldFile(1) - Name of file containing properties for blade 1 (quoted string)
“SWRT_Blade.dat” BldFile(2) - Name of file containing properties for blade 2 (quoted string)
“SWRT_Blade.dat” BldFile(3) - Name of file containing properties for blade 3 (quoted string) [unused for 2 blades]
---------------------- AERODYN -------------------------------------------------
“Test15_AD.ipt” ADFile - Name of file containing AeroDyn input parameters (quoted string)
---------------------- NOISE ---------------------------------------------------
“” NoiseFile - Name of file containing aerodynamic noise input parameters (quoted string) [used only when CompNoise=True]
---------------------- ADAMS ---------------------------------------------------
“” ADAMSFile - Name of file containing ADAMS-specific input parameters (quoted string) [unused when ADAMSPrep=1]
---------------------- LINEARIZATION CONTROL -----------------------------------
“” LinFile - Name of file containing FAST linearization parameters (quoted string) [unused when AnalMode=1]
---------------------- OUTPUT --------------------------------------------------
True SumPrint - Print summary data to “.fsm” (flag)
1 OutFileFmt - Format for tabular (time-marching) output file(s) (1: text file [.out], 2: binary file [.outb], 3: both) (switch)
True TabDelim - Use tab delimiters in text tabular output file? (flag)
“ES10.3E2” OutFmt - Format used for text tabular output (except time). Resulting field should be 10 characters. (quoted string) [not checked for validity!]
50.0 TStart - Time to begin tabular output (s)
4 DecFact - Decimation factor for tabular output {1: output every time step} (-)
1.0 SttsTime - Amount of time between screen status messages (sec)
0.0 NcIMUxn - Downwind distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUyn - Lateral distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUzn - Vertical distance from the tower-top to the nacelle IMU (meters)
0.06 ShftGagL - Distance from rotor apex [3 blades] or teeter pin [2 blades] to shaft strain gages [positive for upwind rotors] (meters)
0 NTwGages - Number of tower nodes that have strain gages for output [0 to 9] (-)
0 TwrGagNd - List of tower nodes that have strain gages [1 to TwrNodes] (-) [unused if NTwGages=0]
0 NBlGages - Number of blade nodes that have strain gages for output [0 to 9] (-)
0 BldGagNd - List of blade nodes that have strain gages [1 to BldNodes] (-) [unused if NBlGages=0]
OutList - The next line(s) contains a list of output parameters. See OutList.xlsx for a listing of available output channels, (-)
“WindVxi”
“WindVyi”
“WindVzi”
“HorWindV”
“HorWndDir”
“TipDxc1”
“TipDyc1”
“TipDzc1”
“TipDxb1”
“TipDyb1”
“TipRDxb1”
“TipRDyb1”
“TipRDzc1”
“TipClrnc1”
“TipDxc2”
“TipDyc2”
“TipDzc2”
“TipDxb2”
“TipDyb2”
“TipRDxb2”
“TipRDyb2”
“TipRDzc2”
“TipClrnc2”
“TipDxc3”
“TipDyc3”
“TipDzc3”
“TipDxb3”
“TipDyb3”
“TipRDxb3”
“TipRDyb3”
“TipRDzc3”
“TipClrnc3”
“BldPitch1”
“BldPitch2”
“BldPitch3”
“Azimuth”
“RotSpeed”
“GenSpeed”
“TSR”
“NcIMUTAxs”
“NcIMUTAys”
“NcIMUTAzs”
“NacYaw”
“NacYawErr”
“TTDspFA”
“TTDspSS”
“TTDspTwst”
“RootFxc1”
“RootFyc1”
“RootFzc1”
“RootFxb1”
“RootFyb1”
“RootMxc1”
“RootMyc1”
“RootMzc1”
“RootMxb1”
“RootMyb1”
“RootFxc2”
“RootFyc2”
“RootFzc2”
“RootFxb2”
“RootFyb2”
“RootMxc2”
“RootMyc2”
“RootMzc2”
“RootMxb2”
“RootMyb2”
“RootFxc3”
“RootFyc3”
“RootFzc3”
“RootFxb3”
“RootFyb3”
“RootMxc3”
“RootMyc3”
“RootMzc3”
“RootMxb3”
“RootMyb3”
“Spn1MLxb1”
“Spn1MLyb1”
“Spn1MLzb1”
“Spn1MLxb2”
“Spn1MLyb2”
“Spn1MLzb2”
“Spn1MLxb3”
“Spn1MLyb3”
“Spn1MLzb3”
“RotThrust”
“LSSGagFys”
“LSSGagFzs”
“RotTorq”
“RotPwr”
“RotCq”
“RotCp”
“RotCt”
“LSSGagMys”
“LSSGagMzs”
“GenTq”
“GenPwr”
“YawBrFzn”
“YawBrFxp”
“YawBrFyp”
“YawBrMzn”
“YawBrMxp”
“YawBrMyp”
“TwrBsFxt”
“TwrBsFyt”
“TwrBsFzt”
“TwrBsMxt”
“TwrBsMyt”
“TwrBsMzt”
“HSShftV”
“HSShftTq”
END of FAST input file (the word “END” must appear in the first 3 columns of this last line).
Dear @Ali.Rouhbakhsh,
The mean values of the blade-root bending moments are the result of thrust and torque and the oscillations about the mean are driven by shaft tilt (skewed flow) and shear.
Best regards,
hi
thanks for response
I changed the tilt angle, which was equal to 3 degrees in my previous modeling, to zero and used a simple wind (pictured below) and disabled everything I could think of that might oscillate the outputs, but Outputs are still fluctuating
Do you have any other recommendations?
Dear @Ali.Rouhbakhsh,
I see that you have active pitch control enabled. Is the pitch varying or held constant?
Oscillations in the blade-root moments can also be caused by gravity.
Best regards,
If the pitch has a fixed value (for example 2 degrees) in a constant wind speed like the picture I sent, does it still have an effect on the fluctuations?
How does gravity affect oscilating results and how can it be disabled?
Dear @Ali.Rouhbakhsh,
Gravity, together with rotor rotation, will effect on the weight of the blade is reflected in the blade-root bending moment. The only way to eliminate the effect is to eliminate gravity (by setting Gravity = 0 in the ENVIRONMENTAL CONDITIONS section of the input file).
The pitch angle will rotate the blade coordinate system relative to the coned/hub coordinated system, which will effect the gravity loads.
Best regards,
In my simulation, the pitch angle converges to a value after passing through the transient region, but still fluctuate
also i changed Gravity value to zero and still oscilate!!!
Is it possible that this has relate to pitch contoller?
[image]
Dear @Ali.Rouhbakhsh,
Your image is not showing up, but variations in the blade root moments will certainly result from variations of blade pitch and variations in rotor speed, even in the absence of gravity, shear, and skewed flow.
Best regards,
hi
Yes, as you correctly said, I referred to the results and saw that there are changes and fluctuations in the speed of the rotor (picture below). Now I want to know what is the cause of these fluctuations? Do you think this might be related to the torque control in the simulink file? Of course, I set the VSContrl parameter in the FAST software input to 2 and set the torque control through the spd_Trq file, but I don’t know why the results are like this.
Dear @Ali.Rouhbakhsh,
There has been much discussion about different settings within FAST in this forum topic, it is difficult for me to understand what settings you are using now. Can you clarify or share your input file(s)?
Best regards,
the primary input file is:
------- FAST INPUT FILE --------------------------------------------------------
FAST certification Test #15: FAST model of a SWRT 3-bladed upwind turbine. Note- SWRT rotates in CCW direction- some inputs will be mirror image of the actual turbine.
Model properties from “SWRTv1p2.adm” and SWRT “AdamsWT_MakeBladeDat_v12.xls”. JEM Jan., 2004. Updated by J. Jonkman, NREL, Feb, 2004. Compatible with FAST v7.02.00.
---------------------- SIMULATION CONTROL --------------------------------------
False Echo - Echo input data to “echo.out” (flag)
1 ADAMSPrep - ADAMS preprocessor mode {1: Run FAST, 2: use FAST as a preprocessor to create an ADAMS model, 3: do both} (switch)
1 AnalMode - Analysis mode {1: Run a time-marching simulation, 2: create a periodic linearized model} (switch)
3 NumBl - Number of blades (-)
650.0 TMax - Total run time (s)
0.005 DT - Integration time step (s)
---------------------- TURBINE CONTROL -----------------------------------------
0 YCMode - Yaw control mode {0: none, 1: user-defined from routine UserYawCont, 2: user-defined from Simulink/Labview} (switch)
0 TYCOn - Time to enable active yaw control (s) [unused when YCMode=0]
2 PCMode - Pitch control mode {0: none, 1: user-defined from routine PitchCntrl, 2: user-defined from Simulink/Labview} (switch)
0 TPCOn - Time to enable active pitch control (s) [unused when PCMode=0]
2 VSContrl - Variable-speed control mode {0: none, 1: simple VS, 2: user-defined from routine UserVSCont, 3: user-defined from Simulink/Labview} (switch)
260 VS_RtGnSp - Rated generator speed for simple variable-speed generator control (HSS side) (rpm) [used only when VSContrl=1]
211.08083 VS_RtTq - Rated generator torque/constant generator torque in Region 3 for simple variable-speed generator control (HSS side) (N-m) [used only when VSContrl=1]
0.0031225 VS_Rgn2K - Generator torque constant in Region 2 for simple variable-speed generator control (HSS side) (N-m/rpm^2) [used only when VSContrl=1]
0.0 VS_SlPc - Rated generator slip percentage in Region 2 1/2 for simple variable-speed generator control (%) [used only when VSContrl=1]
1 GenModel - Generator model {1: simple, 2: Thevenin, 3: user-defined from routine UserGen} (switch) [used only when VSContrl=0]
True GenTiStr - Method to start the generator {T: timed using TimGenOn, F: generator speed using SpdGenOn} (flag)
True GenTiStp - Method to stop the generator {T: timed using TimGenOf, F: when generator power = 0} (flag)
110 SpdGenOn - Generator speed to turn on the generator for a startup (HSS speed) (rpm) [used only when GenTiStr=False]
0.0 TimGenOn - Time to turn on the generator for a startup (s) [used only when GenTiStr=True]
9999.9 TimGenOf - Time to turn off the generator (s) [used only when GenTiStp=True]
1 HSSBrMode - HSS brake model {1: simple, 2: user-defined from routine UserHSSBr, 3: user-defined from Labview} (switch)
9999.9 THSSBrDp - Time to initiate deployment of the HSS brake (s)
9999.9 TiDynBrk - Time to initiate deployment of the dynamic generator brake [CURRENTLY IGNORED] (s)
9999.9 TTpBrDp(1) - Time to initiate deployment of tip brake 1 (s)
9999.9 TTpBrDp(2) - Time to initiate deployment of tip brake 2 (s)
9999.9 TTpBrDp(3) - Time to initiate deployment of tip brake 3 (s) [unused for 2 blades]
9999.9 TBDepISp(1) - Deployment-initiation speed for the tip brake on blade 1 (rpm)
9999.9 TBDepISp(2) - Deployment-initiation speed for the tip brake on blade 2 (rpm)
9999.9 TBDepISp(3) - Deployment-initiation speed for the tip brake on blade 3 (rpm) [unused for 2 blades]
9999.9 TYawManS - Time to start override yaw maneuver and end standard yaw control (s)
9999.9 TYawManE - Time at which override yaw maneuver reaches final yaw angle (s)
0.0 NacYawF - Final yaw angle for yaw maneuvers (degrees)
9999.9 TPitManS(1) - Time to start override pitch maneuver for blade 1 and end standard pitch control (s)
9999.9 TPitManS(2) - Time to start override pitch maneuver for blade 2 and end standard pitch control (s)
9999.9 TPitManS(3) - Time to start override pitch maneuver for blade 3 and end standard pitch control (s) [unused for 2 blades]
9999.9 TPitManE(1) - Time at which override pitch maneuver for blade 1 reaches final pitch (s)
9999.9 TPitManE(2) - Time at which override pitch maneuver for blade 2 reaches final pitch (s)
9999.9 TPitManE(3) - Time at which override pitch maneuver for blade 3 reaches final pitch (s) [unused for 2 blades]
0.0 BlPitch(1) - Blade 1 initial pitch (degrees)
0.0 BlPitch(2) - Blade 2 initial pitch (degrees)
0.0 BlPitch(3) - Blade 3 initial pitch (degrees) [unused for 2 blades]
0.0 BlPitchF(1) - Blade 1 final pitch for pitch maneuvers (degrees)
0.0 BlPitchF(2) - Blade 2 final pitch for pitch maneuvers (degrees)
0.0 BlPitchF(3) - Blade 3 final pitch for pitch maneuvers (degrees) [unused for 2 blades]
---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
9.80665 Gravity - Gravitational acceleration (m/s^2)
---------------------- FEATURE FLAGS -------------------------------------------
True FlapDOF1 - First flapwise blade mode DOF (flag)
True FlapDOF2 - Second flapwise blade mode DOF (flag)
True EdgeDOF - First edgewise blade mode DOF (flag)
False TeetDOF - Rotor-teeter DOF (flag) [unused for 3 blades]
False DrTrDOF - Drivetrain rotational-flexibility DOF (flag)
True GenDOF - Generator DOF (flag)
False YawDOF - Yaw DOF (flag)
True TwFADOF1 - First fore-aft tower bending-mode DOF (flag)
True TwFADOF2 - Second fore-aft tower bending-mode DOF (flag)
True TwSSDOF1 - First side-to-side tower bending-mode DOF (flag)
True TwSSDOF2 - Second side-to-side tower bending-mode DOF (flag)
True CompAero - Compute aerodynamic forces (flag)
False CompNoise - Compute aerodynamic noise (flag)
---------------------- INITIAL CONDITIONS --------------------------------------
0.0 OoPDefl - Initial out-of-plane blade-tip displacement (meters)
0.0 IPDefl - Initial in-plane blade-tip deflection (meters)
0.0 TeetDefl - Initial or fixed teeter angle (degrees) [unused for 3 blades]
0.0 Azimuth - Initial azimuth angle for blade 1 (degrees)
0.0 RotSpeed - Initial or fixed rotor speed (rpm)
0.0 NacYaw - Initial or fixed nacelle-yaw angle (degrees)
0.0 TTDspFA - Initial fore-aft tower-top displacement (meters)
0.0 TTDspSS - Initial side-to-side tower-top displacement (meters)
---------------------- TURBINE CONFIGURATION -----------------------------------
2.562 TipRad - The distance from the rotor apex to the blade tip (meters)
0.15 HubRad - The distance from the rotor apex to the blade root (meters)
1 PSpnElN - Number of the innermost blade element which is still part of the pitchable portion of the blade for partial-span pitch control [1 to BldNodes] [CURRENTLY IGNORED] (-)
0.0 UndSling - Undersling length [distance from teeter pin to the rotor apex] (meters) [unused for 3 blades]
-0.0145 HubCM - Distance from rotor apex to hub mass [positive downwind] (meters)
-0.479 OverHang - Distance from yaw axis to rotor apex [3 blades] or teeter pin [2 blades] (meters)
0.28 NacCMxn - Downwind distance from the tower-top to the nacelle CM (meters)
0.00 NacCMyn - Lateral distance from the tower-top to the nacelle CM (meters)
0.33 NacCMzn - Vertical distance from the tower-top to the nacelle CM (meters)
10.0 TowerHt - Height of tower above ground level [onshore] or MSL [offshore] (meters)
0.398 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (meters)
0.0 TwrRBHt - Tower rigid base height (meters)
-3.0 ShftTilt - Rotor shaft tilt angle (degrees). Negative for an upwind rotor.
0.0 Delta3 - Delta-3 angle for teetering rotors (degrees) [unused for 3 blades]
-5.0 PreCone(1) - Blade 1 cone angle (degrees)
-5.0 PreCone(2) - Blade 2 cone angle (degrees)
-5.0 PreCone(3) - Blade 3 cone angle (degrees) [unused for 2 blades]
0.0 AzimB1Up - Azimuth value to use for I/O when blade 1 points up (degrees)
---------------------- MASS AND INERTIA ----------------------------------------
1.75 YawBrMass - Yaw bearing mass (kg)
263.0 NacMass - Nacelle mass (kg)
51.5 HubMass - Hub mass (kg)
0.0 TipMass(1) - Tip-brake mass, blade 1 (kg)
0.0 TipMass(2) - Tip-brake mass, blade 2 (kg)
0.0 TipMass(3) - Tip-brake mass, blade 3 (kg) [unused for 2 blades]
20.62 NacYIner - Nacelle inertia about yaw axis (kg m^2)
0.5 GenIner - Generator inertia about HSS (kg m^2)
11 HubIner - Hub inertia about rotor axis [3 blades] or teeter axis [2 blades] (kg m^2)
---------------------- DRIVETRAIN ----------------------------------------------
100.0 GBoxEff - Gearbox efficiency (%)
87.0 GenEff - Generator efficiency [ignored by the Thevenin and user-defined generator models] (%)
1.0 GBRatio - Gearbox ratio (-)
False GBRevers - Gearbox reversal {T: if rotor and generator rotate in opposite directions} (flag)
6000 HSSBrTqF - Fully deployed HSS-brake torque (N-m)
0.0 HSSBrDT - Time for HSS-brake to reach full deployment once initiated (sec) [used only when HSSBrMode=1]
“unused” DynBrkFi - File containing a mech-gen-torque vs HSS-speed curve for a dynamic brake [CURRENTLY IGNORED] (quoted string)
5.0E6 DTTorSpr - Drivetrain torsional spring (N-m/rad)
1.0E5 DTTorDmp - Drivetrain torsional damper (N-m/(rad/s))
---------------------- SIMPLE INDUCTION GENERATOR ------------------------------
0.000001 SIG_SlPc - Rated generator slip percentage (%) [used only when VSContrl=0 and GenModel=1]
260 SIG_SySp - Synchronous (zero-torque) generator speed (rpm) [used only when VSContrl=0 and GenModel=1]
446.16 SIG_RtTq - Rated torque (N-m) [used only when VSContrl=0 and GenModel=1]
2 SIG_PORt - Pull-out ratio (Tpullout/Trated) (-) [used only when VSContrl=0 and GenModel=1]
---------------------- THEVENIN-EQUIVALENT INDUCTION GENERATOR -----------------
9999.9 TEC_Freq - Line frequency [50 or 60] (Hz) [used only when VSContrl=0 and GenModel=2]
9998 TEC_NPol - Number of poles [even integer > 0] (-) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SRes - Stator resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RRes - Rotor resistance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_VLL - Line-to-line RMS voltage (volts) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_SLR - Stator leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_RLR - Rotor leakage reactance (ohms) [used only when VSContrl=0 and GenModel=2]
9999.9 TEC_MR - Magnetizing reactance (ohms) [used only when VSContrl=0 and GenModel=2]
---------------------- PLATFORM ------------------------------------------------
0 PtfmModel - Platform model {0: none, 1: onshore, 2: fixed bottom offshore, 3: floating offshore} (switch)
“unused” PtfmFile - Name of file containing platform properties (quoted string) [unused when PtfmModel=0]
---------------------- TOWER ---------------------------------------------------
40 TwrNodes - Number of tower nodes used for analysis (-)
“tower-SWRT-5KW.dat” TwrFile - Name of file containing tower properties (quoted string)
---------------------- NACELLE-YAW ---------------------------------------------
8.471E6 YawSpr - Nacelle-yaw spring constant (N-m/rad)
7930.0 YawDamp - Nacelle-yaw damping constant (N-m/(rad/s))
0.0 YawNeut - Neutral yaw position–yaw spring force is zero at this yaw (degrees)
---------------------- FURLING -------------------------------------------------
False Furling - Read in additional model properties for furling turbine (flag)
“unused” FurlFile - Name of file containing furling properties (quoted string) [unused when Furling=False]
---------------------- ROTOR-TEETER --------------------------------------------
0 TeetMod - Rotor-teeter spring/damper model {0: none, 1: standard, 2: user-defined from routine UserTeet} (switch) [unused for 3 blades]
0.0 TeetDmpP - Rotor-teeter damper position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetDmp - Rotor-teeter damping constant (N-m/(rad/s)) [used only for 2 blades and when TeetMod=1]
0.0 TeetCDmp - Rotor-teeter rate-independent Coulomb-damping moment (N-m) [used only for 2 blades and when TeetMod=1]
0.0 TeetSStP - Rotor-teeter soft-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetHStP - Rotor-teeter hard-stop position (degrees) [used only for 2 blades and when TeetMod=1]
0.0 TeetSSSp - Rotor-teeter soft-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
0.0 TeetHSSp - Rotor-teeter hard-stop linear-spring constant (N-m/rad) [used only for 2 blades and when TeetMod=1]
---------------------- TIP-BRAKE -----------------------------------------------
0.0 TBDrConN - Tip-brake drag constant during normal operation, CdArea (m^2)
0.0 TBDrConD - Tip-brake drag constant during fully-deployed operation, CdArea (m^2)
0.0 TpBrDT - Time for tip-brake to reach full deployment once released (sec)
---------------------- BLADE ---------------------------------------------------
“SWRT_Blade.dat” BldFile(1) - Name of file containing properties for blade 1 (quoted string)
“SWRT_Blade.dat” BldFile(2) - Name of file containing properties for blade 2 (quoted string)
“SWRT_Blade.dat” BldFile(3) - Name of file containing properties for blade 3 (quoted string) [unused for 2 blades]
---------------------- AERODYN -------------------------------------------------
“Test15_AD.ipt” ADFile - Name of file containing AeroDyn input parameters (quoted string)
---------------------- NOISE ---------------------------------------------------
“” NoiseFile - Name of file containing aerodynamic noise input parameters (quoted string) [used only when CompNoise=True]
---------------------- ADAMS ---------------------------------------------------
“” ADAMSFile - Name of file containing ADAMS-specific input parameters (quoted string) [unused when ADAMSPrep=1]
---------------------- LINEARIZATION CONTROL -----------------------------------
“” LinFile - Name of file containing FAST linearization parameters (quoted string) [unused when AnalMode=1]
---------------------- OUTPUT --------------------------------------------------
True SumPrint - Print summary data to “.fsm” (flag)
1 OutFileFmt - Format for tabular (time-marching) output file(s) (1: text file [.out], 2: binary file [.outb], 3: both) (switch)
True TabDelim - Use tab delimiters in text tabular output file? (flag)
“ES10.3E2” OutFmt - Format used for text tabular output (except time). Resulting field should be 10 characters. (quoted string) [not checked for validity!]
50.0 TStart - Time to begin tabular output (s)
4 DecFact - Decimation factor for tabular output {1: output every time step} (-)
1.0 SttsTime - Amount of time between screen status messages (sec)
0.0 NcIMUxn - Downwind distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUyn - Lateral distance from the tower-top to the nacelle IMU (meters)
0.0 NcIMUzn - Vertical distance from the tower-top to the nacelle IMU (meters)
0.06 ShftGagL - Distance from rotor apex [3 blades] or teeter pin [2 blades] to shaft strain gages [positive for upwind rotors] (meters)
0 NTwGages - Number of tower nodes that have strain gages for output [0 to 9] (-)
0 TwrGagNd - List of tower nodes that have strain gages [1 to TwrNodes] (-) [unused if NTwGages=0]
0 NBlGages - Number of blade nodes that have strain gages for output [0 to 9] (-)
0 BldGagNd - List of blade nodes that have strain gages [1 to BldNodes] (-) [unused if NBlGages=0]
OutList - The next line(s) contains a list of output parameters. See OutList.xlsx for a listing of available output channels, (-)
“WindVxi”
“WindVyi”
“WindVzi”
“HorWindV”
“HorWndDir”
“TipDxc1”
“TipDyc1”
“TipDzc1”
“TipDxb1”
“TipDyb1”
“TipRDxb1”
“TipRDyb1”
“TipRDzc1”
“TipClrnc1”
“TipDxc2”
“TipDyc2”
“TipDzc2”
“TipDxb2”
“TipDyb2”
“TipRDxb2”
“TipRDyb2”
“TipRDzc2”
“TipClrnc2”
“TipDxc3”
“TipDyc3”
“TipDzc3”
“TipDxb3”
“TipDyb3”
“TipRDxb3”
“TipRDyb3”
“TipRDzc3”
“TipClrnc3”
“BldPitch1”
“BldPitch2”
“BldPitch3”
“Azimuth”
“RotSpeed”
“GenSpeed”
“TSR”
“NcIMUTAxs”
“NcIMUTAys”
“NcIMUTAzs”
“NacYaw”
“NacYawErr”
“TTDspFA”
“TTDspSS”
“TTDspTwst”
“RootFxc1”
“RootFyc1”
“RootFzc1”
“RootFxb1”
“RootFyb1”
“RootMxc1”
“RootMyc1”
“RootMzc1”
“RootMxb1”
“RootMyb1”
“RootFxc2”
“RootFyc2”
“RootFzc2”
“RootFxb2”
“RootFyb2”
“RootMxc2”
“RootMyc2”
“RootMzc2”
“RootMxb2”
“RootMyb2”
“RootFxc3”
“RootFyc3”
“RootFzc3”
“RootFxb3”
“RootFyb3”
“RootMxc3”
“RootMyc3”
“RootMzc3”
“RootMxb3”
“RootMyb3”
“Spn1MLxb1”
“Spn1MLyb1”
“Spn1MLzb1”
“Spn1MLxb2”
“Spn1MLyb2”
“Spn1MLzb2”
“Spn1MLxb3”
“Spn1MLyb3”
“Spn1MLzb3”
“RotThrust”
“LSSGagFys”
“LSSGagFzs”
“RotTorq”
“RotPwr”
“RotCq”
“RotCp”
“RotCt”
“LSSGagMys”
“LSSGagMzs”
“GenTq”
“GenPwr”
“YawBrFzn”
“YawBrFxp”
“YawBrFyp”
“YawBrMzn”
“YawBrMxp”
“YawBrMyp”
“TwrBsFxt”
“TwrBsFyt”
“TwrBsFzt”
“TwrBsMxt”
“TwrBsMyt”
“TwrBsMzt”
“HSShftV”
“HSShftTq”
END of FAST input file (the word “END” must appear in the first 3 columns of this last line).
Dear @Ali.Rouhbakhsh,
I requested access to your Google drive, but from your FAST v7 primary (*.fst) input file, I see that you know have many DOFs enabled, shaft tilt, gravity, controls, etc., that are can cause oscillations in the response.
Best regards,
