Hi,

I want to generate 1-hour wind files with wind speed 44.2m/s, but after the simulation, I checked the time series, I noticed that the wind speed output is only 33.54m/s, which is far away from my setup wind speed. I attached the time series and wind input file also.

Could you give me some hint what could be the reason for this? Thanks.

TurbSim Input File.

---------Runtime Options-----------------------------------

2250 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)

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)

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-----------------------

31 NumGrid_Z - Vertical grid-point matrix dimension

31 NumGrid_Y - Horizontal grid-point matrix dimension

0.02 TimeStep - Time step [seconds]

3900 AnalysisTime - Length of analysis time series [seconds]

3900 UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds) [bjj: was 630]

123.1 HubHt - Hub height [m] (should be > 0.5*GridHeight)
210 GridHeight - Grid height [m]
210 GridWidth - Grid width [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”=Kaimal, “IECVKM”=von Karman, “GP_LLJ”, “NWTCUP”, “SMOOTH”, “WF_UPW”, “WF_07D”, “WF_14D”, or “NONE”)

1-ed3 IECstandard - Number of IEC 61400-x standard (x=1,2, or 3 with optional 61400-1 edition number (i.e. “1-Ed2”) )

11 IECturbc - IEC turbulence characteristic (“A”, “B”, “C” or the turbulence intensity in percent) (“KHTEST” option with NWTCUP, 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 - Wind profile type (“JET”=Low-level jet,“LOG”=Logarithmic,“PL”=Power law, or “default”, or “USR”=User-defined)

123.1 RefHt - Height of the reference wind speed [m]

44.2 URef - Mean (total) wind speed at the reference height [m/s]

default ZJetMax - Jet height [m] (used only for JET wind profile, valid 70-490 m)

0.14 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”)

0.05 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/s)^2] (or “default”)

default PC_UV - Hub mean u’v’ Reynolds stress [(m/s)^2] (or “default”)

default PC_VW - Hub mean v’w’ Reynolds stress [(m/s)^2] (or “default”)

default IncDec1 - u-component coherence parameters (e.g. “10.0 0.3e-3” in quotes)

default IncDec2 - v-component coherence parameters (e.g. “10.0 0.3e-3” in quotes)

default IncDec3 - w-component coherence parameters (e.g. “10.0 0.3e-3” in quotes)

default CohExp - Coherence exponent (or “default”)

--------Coherent Turbulence Scaling Parameters-------------------

M:\coh_events\eventdata CTEventPath - Name of the path where event data files are located

Random CTEventFile - Type of event files (“random”, “les” or “dns”)

True Randomize - Randomize disturbance scale and location? (true/false)

1 DistScl - Disturbance scale (ratio of dataset height to rotor disk).

0.5 CTLy - Fractional location of tower centerline from right (looking downwind) to left side of the dataset.

0.5 CTLz - Fractional location of hub height from the bottom of the dataset.

10 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]