Generating reasonable wind Fields with TurbSim v2.0 using met mast u-component time series

thanks for the admission.

Currently, I’m working on my master thesis and I require to generate turbulent wind fields using different met mast geometric patterns out of time-series measurements. In other words, I have 4 met mast time-series measurements at different heights (namely B - Bottom, L - Low, H - Hub, T - Top), and I’m using TurbSim v2.0 to generate wind fields taking, for example, the pattern LHT (see 1st fig. attached).

According to my understanding, it is possible to indicate in the .timeser file the number of components, and points. Since I have only u-component time-series, I’m using only the u-component, and three points at the constrained heights (see the first 20 lines of my .timeser file):

[code]--------------TurbSim v2.00.* User Time Series Input File-----------------------

      1  nComp    - Number of velocity components in the file (1=u component only; 2=u & v components; 3=u,v,w) [if < 3 other components will be generated using values from input file]
      3  nPoints  - Number of time series points contained in this file (-)
      2  RefPtID  - Index of the reference point (1-nPoints)

Pointyi Pointzi
(m) (m)
0.00000 15.00000
0.00000 36.60000
0.00000 58.20000
--------Time Series-------------------------------------------------------------
Elapsed Time Point01u Point02u Point03u
(s) (m/s) (m/s) (m/s)
0.00 8.727047 12.574159 14.082604
0.02 8.666645 12.570190 14.127132
0.04 8.623440 12.542412 14.142563
0.06 8.583321 12.508465 14.096272
0.08 8.555546 12.486862 14.009856
0.10 8.524685 12.452913 13.920357[/code]

and my .inp file looks like:

[code]---------TurbSim v2.00.* Input File------------------------
Example input file for TurbSim.
---------Runtime Options-----------------------------------
True Echo - Echo input data to .ech (flag)
95 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)
False 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)
True 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)
True Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)
1 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-----------------------
15 NumGrid_Z - Vertical grid-point matrix dimension
15 NumGrid_Y - Horizontal grid-point matrix dimension
0.02 TimeStep - Time step [seconds]
300 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”)
36.6 HubHt - Hub height [m] (should be > 0.5GridHeight)
60.0 GridHeight - Grid height [m]
60.0 GridWidth - Grid width [m] (should be >= 2
0 VFlowAng - Vertical mean flow (uptilt) angle [degrees]
0 HFlowAng - Horizontal mean flow (skew) angle [degrees]

--------Meteorological Boundary Conditions-------------------
“Timesr” TurbModel - Turbulence model (“IECKAI”,“IECVKM”,“GP_LLJ”,“NWTCUP”,“SMOOTH”,“WF_UPW”,“WF_07D”,“WF_14D”,“TIDAL”,“API”,“USRINP”,“TIMESR”, or “NONE”)
“Wind_TS_V0_7.TimeSer” UserFile - Name of the file that contains inputs for user-defined spectra or time series inputs (used only for “USRINP” and “TIMESR” models)
“1-Ed3” IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. “1-Ed2”) )
“B” 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]
“TS” 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” [-]
36.6 RefHt - Height of the reference velocity (URef) [m]
default URef - Mean (total) velocity at the reference height [m/s] (or “default” for JET velocity profile) [must be 1-hr mean for API model; otherwise is the mean over AnalysisTime seconds]
default ZJetMax - Jet height [m] (used only for JET velocity profile, valid 70-490 m)
default PLExp - Power law exponent [-] (or “default”)
default Z0 - Surface roughness length [m] (or “default”)

--------Non-IEC Meteorological Boundary Conditions------------
default Latitude - Site latitude [degrees] (or “default”)
0.00 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----------------------------
default SCMod1 - u-component coherence model (“GENERAL”, “IEC”, “API”, “NONE”, or “default”)
default SCMod2 - v-component coherence model (“GENERAL”, “IEC”, “NONE”, or “default”)
default SCMod3 - w-component coherence model (“GENERAL”, “IEC”, “NONE”, or “default”)
default InCDec1 - u-component coherence parameters for general or IEC models [-, m^-1] (e.g. “10.0 0.3e-3” in quotes) (or “default”)
default InCDec2 - v-component coherence parameters for general or IEC models [-, m^-1] (e.g. “10.0 0.3e-3” in quotes) (or “default”)
default InCDec3 - w-component coherence parameters for general or IEC models [-, m^-1] (e.g. “10.0 0.3e-3” in quotes) (or “default”)
default CohExp - Coherence exponent for general model [-] (or “default”)

--------Coherent Turbulence Scaling Parameters-------------------
“unused” CTEventPath - Name of the path where event data files are located
“Random” CTEventFile - Type of event files (“LES”, “DNS”, or “RANDOM”)
true Randomize - Randomize the disturbance scale and locations? (true/false)
0 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.)
0 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]

! NOTE: Do not add or remove any lines in this file!

Nevertheless, after running TurbSim v2.0 with such set-up, the output wind fields in the missing components (v and w), are from my point of view unrealistic ( I compared them with wind fields I obtained using TurbSim v1.06, but without a constrained pattern, see 3rd. fig. attached). Therefore, is my concern if my .inp or .timeser file are wrong or I would require to specify the rest of the other components as well in my .timeser file, so TurbSim v2.0 is capable of producing reliable wind fields.

Thank you so much, and I hope you can get my point and assist me.

Daniel Cortés

Dear Daniel,

My understanding is that your don’t like that you are getting zeroes for the v- and w-components. According to the TurbSim v2.0 documentation:

So, you’ll need to specify nComp = 3 and all three velocity time series if you want the TIMESR option to produce nonzero v- and w-components.

Best regards,