following questions
how to analysis fixed botton wind turbine ?
how to consider TMDI effect during analysis under wind and seismic load in turbsim or seismic module ?
Dear @Muhammad.Irfan,
Just a few comments:
- The Seismic functionality of FAST v7 has not yet been migrated over to FAST v8 or OpenFAST.
- The Structural Control (TMD) functionality is available in FAST v8 and OpenFAST, but not in FAST v7
- The version of FAST v7 that supports Seismic functionality can consider a fixed-bottom monopile; FAST v8 and OpenFAST can consider other fixed-bottom offshore systems like tripods and jackets.
Best regards,
Mr jason thanks for your reply
i have some more questions regarding fixed botton ,it is not possible if we do not consider monopile or triople either jackets to check the seismic behaviour of wind turbine tower with nacelle?
can we also consider mechanical inerter or fluid inerter mechanism with TMD in fast or openfast to minimize the vibration of the wind turbine ?
Dear @Muhammad.Irfan,
I’m not sure I understand your question about fixed-bottom systems; please clarify.
The Structural Control (StC) submodel of ServoDyn within OpenFAST considers tuned-mass dampers (TMDs) and tuned liquid column dampers (TLCD). I’m not familiar with the details of how these differ from inerters, but inerters are not directly considered within StC. See the StC documentation for more information: 4.2.12. Structural Control (SrvD) — OpenFAST v3.5.1 documentation.
Best regards,
thanks sir for making clear about all this
@Jason.Jonkman Hello, mr jason. can you tell me how i can find the wind load on the wind turbine as a output concentrated force ? and what is parameter name in output excel file list?
Dear @Muhammad.Irfan,
If you are referring to the total integrated aerodynamic loads applied to the rotor, these are available via AeroDyn outputs RtAeroFxh, etc.
Best regards,
Mr jason , can you use this LSShftFxs as aerodynamic load on wind turbine structure to simulate my model om matlab un wind load ? this is output from elastdyna module ? as shown in above figure
which component of aerodyna module i should adapt to use fixed bottom offshore turbine such as given here in seismic module to choose different options ( PtfmModel - Platform model {0: none, 1: onshore, *: fixed bottom offshore, 3: floating offshore})
i am already using elastdyn and aerodyna module but here i can only find (MHK turbine type (switch) {0=Not an MHK turbine; 1=Fixed MHK turbine; 2=Floating MHK turbine}) this options but i want same as above because i want to generate electricity from wind not from water resourses , please guide me in these few questions
thanks
OpenFAST EXAMPLE INPUT FILE -------------------------------------------
FAST Certification Test #18: NREL 5.0 MW Baseline Wind Turbine (Onshore)
---------------------- SIMULATION CONTROL --------------------------------------
True Echo - Echo input data to .ech (flag)
“FATAL” AbortLevel - Error level when simulation should abort (string) {“WARNING”, “SEVERE”, “FATAL”}
40 TMax - Total run time (s)
0.02 DT - Recommended module time step (s)
2 InterpOrder - Interpolation order for input/output time history (-) {1=linear, 2=quadratic}
0 NumCrctn - Number of correction iterations (-) {0=explicit calculation, i.e., no corrections}
99999 DT_UJac - Time between calls to get Jacobians (s)
1E+06 UJacSclFact - Scaling factor used in Jacobians (-)
---------------------- FEATURE SWITCHES AND FLAGS ------------------------------
1 CompElast - Compute structural dynamics (switch) {1=ElastoDyn; 2=ElastoDyn + BeamDyn for blades}
1 CompInflow - Compute inflow wind velocities (switch) {0=still air; 1=InflowWind; 2=external from OpenFOAM}
2 CompAero - Compute aerodynamic loads (switch) {0=None; 1=AeroDyn v14; 2=AeroDyn v15}
1 CompServo - Compute control and electrical-drive dynamics (switch) {0=None; 1=ServoDyn}
0 CompHydro - Compute hydrodynamic loads (switch) {0=None; 1=HydroDyn}
0 CompSub - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn; 2=External Platform MCKF}
0 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; 2=IceDyn}
1 MHK - MHK turbine type (switch) {0=Not an MHK turbine; 1=Fixed MHK turbine; 2=Floating MHK turbine}
---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
9.80665 Gravity - Gravitational acceleration (m/s^2)
1.225 AirDens - Air density (kg/m^3)
0 WtrDens - Water density (kg/m^3)
1.464E-05 KinVisc - Kinematic viscosity of working fluid (m^2/s)
335 SpdSound - Speed of sound in working fluid (m/s)
103500 Patm - Atmospheric pressure ¶ [used only for an MHK turbine cavitation check]
1700 Pvap - Vapour pressure of working fluid ¶ [used only for an MHK turbine cavitation check]
0 WtrDpth - Water depth (m)
0 MSL2SWL - Offset between still-water level and mean sea level (m) [positive upward]
---------------------- INPUT FILES ---------------------------------------------
“NRELOffshrBsline5MW_Onshore_ElastoDyn.dat” EDFile - Name of file containing ElastoDyn input parameters (quoted string)
“…/5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat” BDBldFile(1) - Name of file containing BeamDyn input parameters for blade 1 (quoted string)
“…/5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat” BDBldFile(2) - Name of file containing BeamDyn input parameters for blade 2 (quoted string)
“…/5MW_Baseline/NRELOffshrBsline5MW_BeamDyn.dat” BDBldFile(3) - Name of file containing BeamDyn input parameters for blade 3 (quoted string)
“…/5MW_Baseline/NRELOffshrBsline5MW_InflowWind_12mps.dat” InflowFile - Name of file containing inflow wind input parameters (quoted string)
“NRELOffshrBsline5MW_Onshore_AeroDyn15.dat” AeroFile - Name of file containing aerodynamic input parameters (quoted string)
“NRELOffshrBsline5MW_Onshore_ServoDyn.dat” ServoFile - Name of file containing control and electrical-drive input parameters (quoted string)
“unused” HydroFile - Name of file containing hydrodynamic input parameters (quoted string)
“unused” SubFile - Name of file containing sub-structural input parameters (quoted string)
“unused” MooringFile - Name of file containing mooring system input parameters (quoted string)
“unused” IceFile - Name of file containing ice input parameters (quoted string)
---------------------- OUTPUT --------------------------------------------------
True SumPrint - Print summary data to “.sum” (flag)
5 SttsTime - Amount of time between screen status messages (s)
99999 ChkptTime - Amount of time between creating checkpoint files for potential restart (s)
“default” DT_Out - Time step for tabular output (s) (or “default”)
0 TStart - Time to begin tabular output (s)
0 OutFileFmt - Format for tabular (time-marching) output file (switch) {0: uncompressed binary [.outb], 1: text file [.out], 2: binary file [.outb], 3: both 1 and 2}
True TabDelim - Use tab delimiters in text tabular output file? (flag) {uses spaces if false}
“ES10.3E2” OutFmt - Format used for text tabular output, excluding the time channel. Resulting field should be 10 characters. (quoted string)
---------------------- LINEARIZATION -------------------------------------------
Dear @Muhammad.Irfan,
ElastoDyn output LSShftFxs includes not only the applied aerodynamic loads, but also the weight and inertia loads of the rotor (projected along the shaft). If you want pure aerodynamic loads, I would use AeroDyn output RtAeroFxh.
To model a fixed-bottom offshore wind turbine in OpenFAST with hydrodynamic loads and structural flexibility of the substructure, you should:
- Enable SubDyn in the OpenFAST glue code and use a SubDyn input file;
- Enable HydroDyn in the OpenFAST glue code and use a HydroDyn input file;
- Enable the six platform degrees of freedom within the ElastoDyn primary input file to enable coupling between the platform reference point in ElastoDyn and the interface joint in SubDyn.
(OpenFAST does not have a direct toggle for fixed-bottom offshore wind, but this is inferred from the SubDyn and HydroDyn settings).
Best regards,
Hello mr , can you please give me reference material to study that what mathematical results in wind turbine tower simulation to find out base shear and base moment?
Dear @Muhammad.Irfan ,
Can you clarify your question? Are you asking how the tower-base loads are computed by the ElastoDyn module of OpenFAST?
Best regards,
yeah such as base moment and base shear , I need its reference material to study and understand its mechanism by mathematical equations
Dear @Muhammad.Irfan,
A high-level explanation of the calculation ElastoDyn uses to calculate tower-base loads is provided in my post dated Sep 5, 2014 in the following forum topic: Tower Base loads. For the full details behind ElastoDyn, find the theory documentation at: 4.2.7. ElastoDyn Users Guide and Theory Manual — OpenFAST v3.5.3 documentation.
Best regards,
all right , thanks ,noted