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Dear @fbelli997, When Best regards, |
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Hi @jjonkman, I was able to solve the issue I previously faced with the non-uniform wind field outside the wake by setting the IEC scale to 2 and ensuring that both simulation and post-processing durations matched the TurbSim-generated time. To remove the initial transient, I ran simulations for twice the TurbSim duration and processed only the second half. However, I've now encountered a new issue. When the simulation reaches around 4000 seconds, it consistently crashes for all tested wind speeds. The error is: Time: 4112 of 10692 seconds. Estimated final completion at 20:04:57. T1:FARM_UpdateStates:FWrap_Increment:FAST_Solution:FAST_UpdateStates:FAST_AdvanceStates:SolveOptio It seems that the wake travels upstream and outside the defined grid. I inspected the last generated VTK files before the crash, and here are the results for two cases (3 m/s and 6 m/s, both with 5% turbulence intensity): As visible, the wake appears discontinuous in both cases. --- AMBIENT WIND: INFLOWWIND MODULE --- [used only for Mod_AmbWind=2 or 3] Do you have any insights into what might be causing this issue? Best regards, |
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Hi everyone,
I'm having some trouble simulating wind fields using TurbSim, and I was hoping to get your insights.
I'm generating wind files for different wind speeds and turbulence intensity levels. The issue is that when I compute the turbulence intensity from the .dat files generated by TurbSim, I consistently get lower TI values than what I specified in the input. In some cases the discrepancy is small (around 0.7–0.8%), but in others the error is more significant.
I'm attaching both:
valutazione_vento.xlsx
Here is how I'm calculating the time step for each case:
and here a plot of the PSD of the wind at 7 m/s.
Furthermore, I tried to decrease the dt_low but with poor results. some of the cases reached very good performance, with a loss in accuracy around 0.7/0.8%, while the others keep more or less constant the loss.
Here the input file:
---------TurbSim v2.00.* Input File------------------------
for user-defined time series input
---------Runtime Options-----------------------------------
False Echo - Echo input data to .ech (flag)
1 RandSeed1 - First random seed (-2147483648 to 2147483647)
"RanLux" RandSeed2 - Second random seed (-2147483648 to 2147483647) for intrinsic pRNG, or an alternative pRNG: "RanLux" or "RNSNLW"
False WrBHHTP - Output hub-height turbulence parameters in binary form? (Generates RootName.bin)
True WrFHHTP - Output hub-height turbulence parameters in formatted form? (Generates RootName.dat)
False WrADHH - Output hub-height time-series data in AeroDyn form? (Generates RootName.hh)
True WrADFF - Output full-field time-series data in TurbSim/AeroDyn form? (Generates RootName.bts)
False WrBLFF - Output full-field time-series data in BLADED/AeroDyn form? (Generates RootName.wnd)
False WrADTWR - Output tower time-series data? (Generates RootName.twr)
False WrFMTFF - Output full-field time-series data in formatted (readable) form? (Generates RootName.u, RootName.v, RootName.w)
False WrACT - Output coherent turbulence time steps in AeroDyn form? (Generates RootName.cts)
False Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)
0 ScaleIEC - Scale IEC turbulence models to exact target standard deviation? [0=no additional scaling; 1=use hub scale uniformly; 2=use individual scales]
--------Turbine/Model Specifications-----------------------
31 NumGrid_Z - Vertical grid-point matrix dimension
101 NumGrid_Y - Horizontal grid-point matrix dimension
2.80 TimeStep - Time step [seconds]
2748.00 AnalysisTime - Length of analysis time series [seconds] (program will add time if necessary: AnalysisTime = MAX(AnalysisTime, UsableTime+GridWidth/MeanHHWS) )
"ALL" UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds unless UsableTime is "ALL")
230 HubHt - Hub height [m] (should be > 0.5GridHeight)
450 GridHeight - Grid height [m]
1500 GridWidth - Grid width(3.2) [m] (should be >= 2(RotorRadius+ShaftLength))
0 VFlowAng - Vertical mean flow (uptilt) angle [degrees]
0 HFlowAng - Horizontal mean flow (skew) angle [degrees]
--------Meteorological Boundary Conditions-------------------
"IECKAI" TurbModel - Turbulence model ("IECKAI","IECVKM","GP_LLJ","NWTCUP","SMOOTH","WF_UPW","WF_07D","WF_14D","TIDAL","API","USRINP","TIMESR", or "NONE")
"-----" UserFile - Name of the file that contains inputs for user-defined spectra or time series inputs (used only for "USRINP" and "TIMESR" models)
1 IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. "1-Ed2") )
15.00 IECturbc - IEC turbulence characteristic ("A", "B", "C" or the turbulence intensity in percent) ("KHTEST" option with NWTCUP model, not used for other models)
"NTM" IEC_WindType - IEC turbulence type ("NTM"=normal, "xETM"=extreme turbulence, "xEWM1"=extreme 1-year wind, "xEWM50"=extreme 50-year wind, where x=wind turbine class 1, 2, or 3)
"default" ETMc - IEC Extreme Turbulence Model "c" parameter [m/s]
"PL" WindProfileType - Velocity profile type ("LOG";"PL"=power law;"JET";"H2L"=Log law for TIDAL model;"API";"USR";"TS";"IEC"=PL on rotor disk, LOG elsewhere; or "default")
"unused" ProfileFile - Name of the file that contains input profiles for WindProfileType="USR" and/or TurbModel="USRVKM" [-]
155 RefHt - Height of the reference velocity (URef) [m]
7.00 URef - Mean (total) velocity at the reference height [m/s] (or "default" for JET velocity profile)
350 ZJetMax - Jet height [m] (used only for JET velocity profile, valid 70-490 m)
"0.00" PLExp - Power law exponent [-] (or "default")
"0.011" Z0 - Surface roughness length [m] (or "default")
--------Non-IEC Meteorological Boundary Conditions------------
"default" Latitude - Site latitude [degrees] (or "default")
0.05 RICH_NO - Gradient Richardson number [-]
"default" UStar - Friction or shear velocity [m/s] (or "default")
"default" ZI - Mixing layer depth [m] (or "default")
"default" PC_UW - Hub mean u'w' Reynolds stress [m^2/s^2] (or "default" or "none")
"default" PC_UV - Hub mean u'v' Reynolds stress [m^2/s^2] (or "default" or "none")
"default" PC_VW - Hub mean v'w' Reynolds stress [m^2/s^2] (or "default" or "none")
--------Spatial Coherence Parameters----------------------------
"IEC" SCMod1 - u-component coherence model ("GENERAL","IEC","API","NONE", or "default")
"IEC" SCMod2 - v-component coherence model ("GENERAL","IEC","NONE", or "default")
"IEC" SCMod3 - w-component coherence model ("GENERAL","IEC","NONE", or "default")
"12, 3.5273e-4" InCDec1 - u-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
"12, 3.5273e-4" InCDec2 - v-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
"12, 3.5273e-4" InCDec3 - w-component coherence parameters for general or IEC models [-, m^-1] (e.g. "10.0 0.3e-3" in quotes) (or "default")
0 CohExp - Coherence exponent for general model [-] (or "default")
--------Coherent Turbulence Scaling Parameters-------------------
".\EventData" CTEventPath - Name of the path where event data files are located
"les" CTEventFile - Type of event files ("LES", "DNS", or "RANDOM")
true Randomize - Randomize the disturbance scale and locations? (true/false)
1 DistScl - Disturbance scale [-] (ratio of event dataset height to rotor disk). (Ignored when Randomize = true.)
0.5 CTLy - Fractional location of tower centerline from right [-] (looking downwind) to left side of the dataset. (Ignored when Randomize = true.)
0.5 CTLz - Fractional location of hub height from the bottom of the dataset. [-] (Ignored when Randomize = true.)
10 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]
====================================================
! NOTE: Do not add or remove any lines in this file!
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