Extending 10-minute wind field to 6 hours

Topics of general, but wind-related interest.

Moderator: Bonnie.Jonkman

Evgeniy.Dimkin
Posts: 6
Joined: Mon Oct 09, 2017 10:57 am
Organization: DNV GL
Location: United Kingdom

Extending 10-minute wind field to 6 hours

Postby Evgeniy.Dimkin » Tue Oct 10, 2017 8:14 am

Hello everyone.

I am new to FAST and have a problem I have been unable to solve for the past couple of days. I am trying to extend a 600s simulation to 6 hours in a .bts file.

I have downloaded TurbSim and have used the PERL script to generate 36 seeds. I renamed the PERL script accordingly and set out to run the input file. The problem is that once I decide to use the generated .bts file in a FAST simulation, my wind field runs out at 601s out of 21600s. The reason is that my input file is specified at 600s Analysis time and Usable time, which would be a standard 10-minute wind field generated by TurbSim.

My question is this: How do I extend the wind field to 21600s. I thought that the Perl script does that for me and compiles the .bts file.

Below are my Perl script and initial input file .inp. I really would appreciate any help you can offer!

TurbSim Input File. Valid for TurbSim v1.50; 17-May-2010; Example file that can be used with simulations for the NREL 5MW Baseline Turbine; note that UsableTime has been decreased in this file so that the file distributed with the FAST CertTest isn't as large

---------Runtime Options-----------------------------------
13428 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)
True 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)
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
31 NumGrid_Y - Horizontal grid-point matrix dimension
0.05 TimeStep - Time step [seconds]
630.0 AnalysisTime - Length of analysis time series [seconds]
600.0 UsableTime - Usable length of output time series [seconds] (program will add GridWidth/MeanHHWS seconds) [bjj: was 630]
90.0 HubHt - Hub height [m] (should be > 0.5*GridHeight)
145.0 GridHeight - Grid height [m]
145.0 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") )
"B" IECturbc - IEC turbulence characteristic ("A", "B", "C" or the turbulence intensity in percent) ("KHTEST" option with NWTCUP, not used for other models)
3EWM50 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)
90. RefHt - Height of the reference wind speed [m]
31.0 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)
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")
0.05 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) (or "default")
default IncDec2 - v-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default IncDec3 - w-component coherence parameters (e.g. "10.0 0.3e-3" in quotes) (or "default")
default CohExp - Coherence exponent (or "default")

--------Coherent Turbulence Scaling Parameters-------------------
"C:\Users\EVGDIM\Desktop\FAST + Orcaflex\TurbSim\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)
1.0 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.
10.0 CTStartTime - Minimum start time for coherent structures in RootName.cts [seconds]

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

PERL SCRIPT

# RunTurbSim.pl
# See Marshall Buhl's RunNTM Perl script for help with this script.
# Run a series of TurbSim tests, changing the seed for each case.

# NOTICE
# ------
# Look for the string "USER" for lines that you may want to change.


#-------------------------------------------------------------------
# User-specified paths to programs and files. USER: YOU WILL DEFINITELY NEED TO CHANGE THESE.
#-------------------------------------------------------------------

$turbsim = "TurbSim";

# The TurbSim input/output file name:
$input_file = "C:/Users/EVGDIM/Desktop/FAST + Orcaflex/TurbSim/90m_37mps_50yr.inp";

# The Directory to place results in:
$rslt_dir = "C:/Users/EVGDIM/Desktop/FAST + Orcaflex/TurbSim/Results Seeds";

# The name of the resulting file in the results directory (will be appended with the seed number)
$rslt_file = "37mps_TurbS_CTS_50yr";

# The extensions of TurbSim output to copy to the results directory:
#@out_ext = ("inp","sum","wnd","cts");
@out_ext = ("sum","wnd","cts");

#-------------------------------------------------------------------
# Set the number of seeds to run. Initialize the first seed. USER: YOU MAY WANT TO CHANGE THESE
#-------------------------------------------------------------------

$seed_1 = 816416316;
$n_seeds = 36;

#-------------------------------------------------------------------
# Get and save the start time. Initialize other variables
#-------------------------------------------------------------------

$StartTime = date_time();
$n_runs = 0;
$seed_line = 4;

srand($seed_1);
#===================================================================
# Loop through all seeds.
#===================================================================

for $i_seed ( 1..$n_seeds )
{

$ts_root = "${rslt_file}";

#-------------------------------------------------------------------
# Create TurbSim Input File
#-------------------------------------------------------------------

$in_file = "${ts_root}.inp";

open( IN_FILE , ">$in_file" ) or die( "Can't open '$in_file'.\n" );
open( IN_FILE1, "$input_file" ) or die( "Can't open '$input_file'.\n" );


$cnt = 1;

while ( <IN_FILE1> )
{
if ( $cnt == $seed_line )
{
printf ( IN_FILE "%s\t%s\n", "$seed_1", "The first seed" );
}
else
{
print IN_FILE;
}

$cnt++;

} # while <IN_FILE1>

close( IN_FILE );
close( IN_FILE1 );


#-------------------------------------------------------------------
# Run TurbSim
#-------------------------------------------------------------------

print "\n ==============================================\n";
print " TurbSim Seed $i_seed = $seed_1 \n";
print " ==============================================\n";
print " Starting TurbSim on ", date_time(), ".\n";
system( "$turbsim $ts_root.inp > NUL" );

#-------------------------------------------------------------------
# Rename output
#-------------------------------------------------------------------

$root = sprintf( "%s/%s_%s", $rslt_dir, $ts_root, $i_seed);

for $i_r ( 0..$#out_ext )
{
rename( "$ts_root.$out_ext[$i_r]" , "$root.$out_ext[$i_r]" );
}

#-------------------------------------------------------------------
# Get next seed
#-------------------------------------------------------------------

$seed_1 = int( rand(2147483646) ) + 1;

$n_runs ++;


# End of $i_seed loop
}


#-------------------------------------------------------------------
# Done.
#-------------------------------------------------------------------

print "\n ============================================\n";
if ( $n_runs > 1 )
{
print " After starting on $StartTime, the $n_runs batch runs\n";
print " completed on ", date_time(), ".\n\n";
}
else
{
print " The single batch run completed on ", date_time(), ".\n\n";
}

#-------------------------------------------------------------------
# End of main function.
#-------------------------------------------------------------------

#*******************************************************************
#*******************************************************************
# This routine returns the date and time in the form "dd-Mon-ccyy at hh:mm:ss".

sub date_time
{
my( $sec, $min, $hour, $mday, $mon, $year, $mon_str );

($sec, $min, $hour, $mday, $mon, $year) = localtime;

$mon_str = (Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec)[$mon];

return sprintf( "%2.2d-%s-%4.4d at %2.2d:%2.2d:%2.2d", $mday, $mon_str, $year+1900, $hour, $min, $sec );
}

__END__

Jason.Jonkman
Posts: 5170
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Extending 10-minute wind field to 6 hours

Postby Jason.Jonkman » Tue Oct 10, 2017 1:18 pm

Dear Evgeniy,

The script you are using will generate 36 unique TurbSim output (*.bts) files with which you can run 36 unique FAST simulations, each of 600 s in length. The script will not concatenate the TurbSim files into a single file for running longer FAST simulations (nor would you want to as the flow would be discontinuous where the files are concatenated.

To run longer FAST simulations, you could either run TurbSim for longer (more than 600 s) or use periodic wind data files i.e. wind is repeated periodically over the total FAST simulation length. For the latter, the ability to generate periodic wind files was introduced in TurbSim v2.00 and newer, available from here: https://nwtc.nrel.gov/alphas. Simply set TurbSim input UsableTime to the string, "ALL" and run TurbSim to generate periodic wind data files useable by FAST.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Evgeniy.Dimkin
Posts: 6
Joined: Mon Oct 09, 2017 10:57 am
Organization: DNV GL
Location: United Kingdom

Re: Extending 10-minute wind field to 6 hours

Postby Evgeniy.Dimkin » Wed Oct 11, 2017 10:33 am

Dear Jason,

thank you very much for the help and fast response. The model does run now for longer periods of time.

I tried running a 3-hour simulation. Everything was ok until my simulation reached near 10 000 seconds of 10 800s and I got the following error below. Could you please advise?

Code: Select all

C:BeddoesModel:ATT
ACH: Blade #1 element #17 is supersonic!  Other elements are likely supersonic a
s well.
Supersonic mach nos. will be set to 0.7 to attempt continuation.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Supersonic condition has subsided w
ith Blade #2
element #4.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Blade #1 element #17 is supersonic!  Other elements are likely supersonic a
s well.
Supersonic mach nos. will be set to 0.7 to attempt continuation.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Supersonic condition has subsided w
ith Blade #2
element #4.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Blade #3 element #17 is supersonic!  Other elements are likely supersonic a
s well.
Supersonic mach nos. will be set to 0.7 to attempt continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #17 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #16 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #15 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.


FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #14 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.

  WARNING:   High VT velocity encountered during induction factor calculation.
  Blade number 1, Element number 17
  VNW = 36.185, VT = 412.7
  WARNING:   High VT velocity encountered during induction factor calculation.
  Blade number 2, Element number 17
  VNW = 30.494, VT = 405.2
  WARNING:   High VT velocity encountered during induction factor calculation.
  Blade number 3, Element number 13
  VNW = 41.093, VT = 454.81
  WARNING:   High VT velocity encountered during induction factor calculation.
  Blade number 3, Element number 14
  VNW = 40.533, VT = 516.39
  WARNING:   High VNB velocity encountered during induction factor calculation.
  Blade number 3, Element number 15
  VNW = 39.772, VNB = 130.88
  WARNING:   Induced velocity warning written 5 times.  The message will not be
repeated, though
 the condition may persist.

FAST_Solution:CalcOutputs_And_SolveForInputs:SolveOption2:AD14_CalcOutput:ELEMFR
C:BeddoesModel:ATT
ACH: Supersonic condition has subsided with Blade #1 element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #1 element #15 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Supersonic condition has subsided w
ith Blade #2
element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #2 element #15 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Supersonic condition has subsided w
ith Blade #3
element #4.
AD14_CalcOutput:ELEMFRC:BeddoesModel:ATTACH: Blade #3 element #11 is supersonic!
  Other elements
are likely supersonic as well. Supersonic mach nos. will be set to 0.7 to attemp
t continuation.
forrtl: severe (157): Program Exception - access violation
Image              PC                Routine            Line        Source

FAST_x64.exe       0000000140C8F786  Unknown               Unknown  Unknown
FAST_x64.exe       0000000140C8DC41  Unknown               Unknown  Unknown
FAST_x64.exe       0000000140C8B8DD  Unknown               Unknown  Unknown
FAST_x64.exe       0000000140C88959  Unknown               Unknown  Unknown
FAST_x64.exe       00000001400D6C2D  Unknown               Unknown  Unknown
FAST_x64.exe       00000001400D55E4  Unknown               Unknown  Unknown
FAST_x64.exe       000000014004EAB0  Unknown               Unknown  Unknown
FAST_x64.exe       000000014003AD98  MAIN__                    132  FAST_Prog.f9
0
FAST_x64.exe       000000013FC8A2B6  Unknown               Unknown  Unknown
FAST_x64.exe       0000000141016EAC  Unknown               Unknown  Unknown
kernel32.dll          00000000779859CD  Unknown                Unknown  Unknown
ntdll.dll                0000000077ABA561  Unknown                Unknown  Unknown

Jason.Jonkman
Posts: 5170
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Extending 10-minute wind field to 6 hours

Postby Jason.Jonkman » Wed Oct 11, 2017 10:56 am

Dear Evgeniy,

I'm not sure; without knowing more about your simulation settings, it's hard to know that what the problem is. But warnings regarding “supersonic blades” have been discussed several times on this forum. Please use "Search..." in the upper right of the forum to search for "supersonic" to see how we've solved similar problems in the past.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Evgeniy.Dimkin
Posts: 6
Joined: Mon Oct 09, 2017 10:57 am
Organization: DNV GL
Location: United Kingdom

Re: Extending 10-minute wind field to 6 hours

Postby Evgeniy.Dimkin » Fri Oct 13, 2017 9:29 am

Dear Jason,

thank you for your fast reply and help. Apologies for my late reply as I didn't want to post anything before I had come up with some solution or at least positive progress. I managed to solve the problem by looking at the FAST input file .fst and extending the Checkpoint creation file "ChkptTime" from 9999 to 99999.

I did the same in the ServoDyn.dat file. I looked at all 9999 values with units of time and increased to 99999, where it made sense, given the function description in the standard input file.

The reason for doing this was the suspicious time instance at which the simulation always crashed regardless of all other inputs. The crash always occurred at 10 000s.

Given that the error I posted above for the supersonic blades, detailed one of the FAST source scripts - FAST_Prog.f90 Line 132, which deals with time step issues, as a potential source for the crash. In addition to OrcaFlex visualisation of the simulation run, up to the point before it crashed, which showed that everything was in order, my only conclusion was the way the OC3 Hywind file was designed with a 4-digit limit as the maximum simulation time possible across all modules. Going from a 4-digit max simulation time to a 5-digit limit made sense in my mind.

Does this sound as a reasonable solution to you?

Jason.Jonkman
Posts: 5170
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

Re: Extending 10-minute wind field to 6 hours

Postby Jason.Jonkman » Fri Oct 13, 2017 10:02 am

Dear Evgeniy,

My guess is it was the changes you made to input parameters in ServoDyn (from 9999 to 99999 s) that solved the problem i.e. you were likely initiating a control action that you had not intended. I would not expect that the generation of a checkpoint file would cause a problem.

I'm not sure I understand your point about the FAST source code.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Evgeniy.Dimkin
Posts: 6
Joined: Mon Oct 09, 2017 10:57 am
Organization: DNV GL
Location: United Kingdom

Re: Extending 10-minute wind field to 6 hours

Postby Evgeniy.Dimkin » Fri Oct 13, 2017 11:33 am

Dear Jason,

I simply meant to say that the following lines from the error message:

forrtl: severe (157): Program Exception - access violation
Image PC Routine Line Source

FAST_x64.exe 0000000140C8F786 Unknown Unknown Unknown
FAST_x64.exe 0000000140C8DC41 Unknown Unknown Unknown
.
.
.
FAST_x64.exe 000000014003AD98 MAIN__ 132 FAST_Prog.f90

Made me think that something was wrong with the time step specifications. Line 132 accounts for time steps, thus I figured I had not specified the max time limit appropriately in some of the FAST modules.

Again, thank you very much for your help! :) Have a great weekend!


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