4.1.2. API changes between versions

This page lists the main changes in the OpenFAST API (input files) between different versions.

The changes are tabulated according to the module input file, line number, and flag name. The line number corresponds to the resulting line number after all changes are implemented. Thus, be sure to implement each in order so that subsequent line numbers are correct.

4.1.2.1. OpenFAST v3.5.1 to OpenFAST v3.5.2

No input file changes were made.

4.1.2.2. OpenFAST v3.5.0 to OpenFAST v3.5.1

No input file changes were made. Some input files now include additional output channels: AeroDyn nodal outputs for another coordinate system, new MoorDyn output names (Connect changed to Point).

4.1.2.3. OpenFAST v3.4.0 to OpenFAST v3.5.0

Updated the CMake build system. Now requires CMake v3.12 or higher.

Modified in OpenFAST 3.5.0

Module

Line

Flag Name

Example Value

ServoDyn-StructCtrl

6

StC_DOF_MODE

2 StC_DOF_MODE - DOF mode (switch) {0: No StC or TLCD DOF; 1: StC_X_DOF, StC_Y_DOF, and/or StC_Z_DOF (three independent StC DOFs); 2: StC_XY_DOF (Omni-Directional StC); 3: TLCD; 4: Prescribed force/moment time series; 5: Force determined by external DLL}

InflowWind

8

VelInterpCubic

true VelInterpCubic - Use cubic interpolation for velocity in time (false=linear, true=cubic) [Used with WindType=2,3,4,5,7]

InflowWind

51

================== LIDAR Parameters ===========================================================================

InflowWind

52

SensorType

0 SensorType - Switch for lidar configuration (0 = None, 1 = Single Point Beam(s), 2 = Continuous, 3 = Pulsed)

InflowWind

53

NumPulseGate

0 NumPulseGate - Number of lidar measurement gates (used when SensorType = 3)

InflowWind

54

PulseSpacing

30 PulseSpacing - Distance between range gates (m) (used when SensorType = 3)

InflowWind

55

NumBeam

0 NumBeam - Number of lidar measurement beams (0-5)(used when SensorType = 1)

InflowWind

56

FocalDistanceX

-200 FocalDistanceX - Focal distance co-ordinates of the lidar beam in the x direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)

InflowWind

57

FocalDistanceY

0 FocalDistanceY - Focal distance co-ordinates of the lidar beam in the y direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)

InflowWind

58

FocalDistanceZ

0 FocalDistanceZ - Focal distance co-ordinates of the lidar beam in the z direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)

InflowWind

59

RotorApexOffsetPos

0.0 0.0 0.0 RotorApexOffsetPos - Offset of the lidar from hub height (m)

InflowWind

60

URefLid

17 URefLid - Reference average wind speed for the lidar[m/s]

InflowWind

61

MeasurementInterval

0.25 MeasurementInterval - Time between each measurement [s]

InflowWind

62

LidRadialVel

False LidRadialVel - TRUE => return radial component, FALSE => return ‘x’ direction estimate

InflowWind

63

ConsiderHubMotion

1 ConsiderHubMotion - Flag whether to consider the hub motion’s impact on Lidar measurements

4.1.2.4. OpenFAST v3.4.0 to OpenFAST v3.4.1

Restored the AeroDyn channel names with Aero in the name. These had be changed to Fld in v3.4.0 which caused headaches for users. The Fld names are now aliases to the Aero names.

4.1.2.5. OpenFAST v3.3.0 to OpenFAST v3.4.0

Added in OpenFAST 3.4.0

Module

Line

Flag Name

Example Value

FAST.Farm

42*

ModWake

1 Mod_Wake - Switch between wake formulations {1:Polar, 2:Curl, 3:Cartesian} (-) (switch)

FAST.Farm

67

CurlSection

— CURLED-WAKE PARAMETERS [only used if Mod_Wake=2 or 3] —

FAST.Farm

68

Swirl

DEFAULT Swirl - Switch to include swirl velocities in wake (-) (switch) [DEFAULT=True]

FAST.Farm

69

k_VortexDecay

DEFAULT k_VortexDecay - Vortex decay constant for curl (-) [DEFAULT=0.01] [only used if Mod_Wake=2]

FAST.Farm

70

NumVortices

DEFAULT NumVortices - The number of vortices in the curled wake model (-) [DEFAULT=100] [only used if Mod_Wake=2]

FAST.Farm

71

sigma_D

DEFAULT sigma_D - The width of the vortices in the curled wake model non-dimensionalized by rotor diameter (-) [DEFAULT=0.2] [only used if Mod_Wake=2]

FAST.Farm

72

FilterInit

DEFAULT FilterInit - Switch to filter the initial wake plane deficit and select the number of grid points for the filter {0: no filter, 1: filter of size 1} or DEFAULT [DEFAULT=1] (switch)

FAST.Farm

73

k_vCurl

DEFAULT k_vCurl - Calibrated parameter for scaling the eddy viscosity in the curled-wake model (-) [>=0] or DEFAULT [DEFAULT=2.0 ]

FAST.Farm

74

Mod_Projection

DEFAULT Mod_Projection - Switch to select how the wake plane velocity is projected in AWAE {1: keep all components, 2: project against plane normal} or DEFAULT [DEFAULT=1: if Mod_Wake is 1 or 3, or DEFAULT=2: if Mod_Wake is 2] (switch)

FAST.Farm

91

OutAllPlanes

DEFAULT OutAllPlanes - Output all wake planes at all time steps. [DEFAULT=False]

AeroDyn 15

13

Buoyancy

True Buoyancy - Include buoyancy effects? (flag)

AeroDyn 15

65

HubPropsSection

====== Hub Properties ============================================================================== [used only when Buoyancy=True]

AeroDyn 15

66

VolHub

7.0 VolHub - Hub volume (m^3)

AeroDyn 15

67

HubCenBx

0.5 HubCenBx - Hub center of buoyancy x direction offset (m)

AeroDyn 15

68

NacPropsSection

====== Nacelle Properties ========================================================================== [used only when Buoyancy=True]

AeroDyn 15

69

VolNac

32.0 VolNac - Nacelle volume (m^3)

AeroDyn 15

70

NacCenB

0.4,0,0 NacCenB - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)

AeroDyn 15

71

TFinPropsSection

====== Tail fin Aerodynamics ========================================================================

AeroDyn 15

72

TFinAero

True TFinAero - Calculate tail fin aerodynamics model (flag)

AeroDyn 15

73

TFinFile$

“AD_Fin.dat” TFinFile - Input file for tail fin aerodynamics [used only when TFinAero=True]

AeroDyn 15

TwrCb

1.0 [additional column in Tower Influence and Aerodynamics table]

AeroDyn blade

BlCb

0.187 [additional column in Blade Properties table]

AeroDyn blade

BlCenBn

0.3 [additional column in Blade Properties table]

AeroDyn blade

BlCenBt

0.1 [additional column in Blade Properties table]

OLAF

18

nNWPanelFree

180 nNWPanelFree - Number of free near-wake panels (-) {default: nNWPanels}

OLAF

19

nFWPanels

900 nFWPanels - Number of far-wake panels (-) {default: 0}

OLAF

20

nFWPanelsFree

0 nFWPanelsFree - Number of free far-wake panels (-) {default: nFWPanels}

*Exact line number depends on number of entries in various preceeding tables.

$ The content of the tail fin input file is described in Section 4.2.1.3.5.

New Default Values: The following default value were changed

  • OLAF VelocityMethod is now 2 (particle tree), previous value 1 (n^2 BiotSavart law on segments).

  • OLAF WakeRegMethod is now 3 (increasing with wake age), previous value was 1 (constant).

  • OLAF nVTKBlades is now 0 (no wake panels output), previous value was 1 (wake panels output for blade 1)

Removed in OpenFAST v3.4.0

Module

Line

Flag Name

Example Value

OLAF

18

WakeLength

900 WakeLength Total wake distance [integer] (number of time steps)

OLAF

19

FreeWakeLength

0 FreeWakeLength Wake length that is free [integer] (number of time steps) {default: WakeLength}

4.1.2.6. OpenFAST v3.2.0 to OpenFAST v3.3.0

Added in OpenFAST 3.3.0

Module

Line

Flag Name

Example Value

FAST.Farm

9

ModWaveField

2 Mod_WaveField - Wave field handling (-) (switch) {1: use individual HydroDyn inputs without adjustment, 2: adjust wave phases based on turbine offsets from farm origin}

FAST.Farm

10

Mod_SharedMooring

0 Mod_SharedMooring - Shared mooring system model (switch) {0: None, 3=MoorDyn}}

FAST.Farm

13

na

—— SHARED MOORING SYSTEM —— [used only for Mod_SharedMoor>0]

FAST.Farm

14

SharedMoorFile

“” SharedMoorFile - Name of file containing shared mooring system input parameters (quoted string) [used only when Mod_SharedMooring > 0]

FAST.Farm

15

DT_Mooring

0.04 DT_Mooring - Time step for farm-level mooring coupling with each turbine (s) [used only when Mod_SharedMooring > 0]

AeroDyn driver

54*

WrVTK_Type

1 WrVTK_Type - VTK visualization data type: (switch) {1=surfaces; 2=lines; 3=both}

Modified in OpenFAST v3.3.0

Module

Line

Flag Name

Example Value

MoorDyn&

5

na

Name Diam MassDen EA BA/-zeta EI Cd Ca CdAx CaAx

MoorDyn&

6

na

(-) (m) (kg/m) (N) (N-s/-) (-) (-) (-) (-) (-)

MoorDyn&

7

na

main 0.0766 113.35 7.536E8 -1.0 0 2.0 0.8 0.4 0.25

MoorDyn&

8*

na

———————- POINTS ——————————–

MoorDyn&

9*

na

ID Attachment X Y Z M V CdA CA

MoorDyn&

10*

na

(-) (-) (m) (m) (m) (kg) (m^3) (m^2) (-)

MoorDyn&

11*

na

1 Fixed 418.8 725.383 -200.0 0 0 0 0

MoorDyn&

17*

na

———————- LINES ————————————–

MoorDyn&

18*

na

ID LineType AttachA AttachB UnstrLen NumSegs Outputs

MoorDyn&

19*

na

(-) (-) (-) (-) (m) (-) (-)

MoorDyn&

20*

na

1 main 1 4 835.35 20 -

&MoorDyn has undergone an extensive revision that leaves few lines unchanged. We recommend looking at a sample input file for the 5MW_OC4Semi_WSt_WavesWN regression test for reference rather than line by line changes in the above tables.

Removed in OpenFAST v3.3.0

Module

Line

Flag Name

Example Value

MoorDyn&

5

NTypes

1 NTypes - number of LineTypes

MoorDyn&

10*

NConnects

6 NConnects - number of connections including anchors and fairleads

MoorDyn&

20*

NLines

3 NLines - number of line objects

*Exact line number depends on number of entries in various preceeding tables.

&MoorDyn has undergone an extensive revision that leaves few lines unchanged. We recommend looking at a sample input file for the 5MW_OC4Semi_WSt_WavesWN regression test for reference rather than line by line changes in the above tables.

4.1.2.7. OpenFAST v3.1.0 to OpenFAST v3.2.0

Added in OpenFAST v3.2.0

Module

Line

Flag Name

Example Value

TurbSim

13

WrHAWCFF

False WrHAWCFF - Output full-field time-series data in HAWC form? (Generates RootName-u.bin, RootName-v.bin, RootName-w.bin, RootName.hawc)

Removed in OpenFAST v3.2.0

Module

Line

Flag Name

Example Value

TurbSim

14

Clockwise

True Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)

4.1.2.8. OpenFAST v3.0.0 to OpenFAST v3.1.0

Added in OpenFAST v3.1.0

Module

Line

Flag Name

Example Value

ServoDyn

60

AeroControlSec

———————- AERODYNAMIC FLOW CONTROL ——————————–

ServoDyn

61

AfCmode

0 AfCmode - Airfoil control mode {0: none, 1: cosine wave cycle, 4: user-defined from Simulink/Labview, 5: user-defined from Bladed-style DLL} (switch)

ServoDyn

62

AfC_Mean

0 AfC_Mean - Mean level for cosine cycling or steady value (-) [used only with AfCmode==1]

ServoDyn

63

AfC_Amp

0 AfC_Amp - Amplitude for cosine cycling of flap signal (-) [used only with AfCmode==1]

ServoDyn

64

AfC_Phase

0 AfC_Phase - Phase relative to the blade azimuth (0 is vertical) for cosine cycling of flap signal (deg) [used only with AfCmode==1]

ServoDyn

74

CablesSection

———————- CABLE CONTROL ——————————————-

ServoDyn

75

CCmode

0 CCmode - Cable control mode {0: none, 4: user-defined from Simulink/Labview, 5: user-defined from Bladed-style DLL} (switch)

HydroDyn driver

6

WtrDens

1025 WtrDens - Water density (kg/m^3)

HydroDyn driver

7

WtrDpth

200 WtrDpth - Water depth (m)

HydroDyn driver

8

MSL2SWL

0 MSL2SWL - Offset between still-water level and mean sea level (m) [positive upward]

OpenFAST

21

MHK

0 MHK - MHK turbine type (switch) {0=Not an MHK turbine; 1=Fixed MHK turbine; 2=Floating MHK turbine}

OpenFAST

22

EnvCondSection

———————- ENVIRONMENTAL CONDITIONS ——————————–

OpenFAST

23

Gravity

9.80665 Gravity - Gravitational acceleration (m/s^2)

OpenFAST

24

AirDens

1.225 AirDens - Air density (kg/m^3)

OpenFAST

25

WtrDens

1025 WtrDens - Water density (kg/m^3)

OpenFAST

26

KinVisc

1.464E-05 KinVisc - Kinematic viscosity of working fluid (m^2/s)

OpenFAST

27

SpdSound

335 SpdSound - Speed of sound in air (m/s)

OpenFAST

28

Patm

103500 Patm - Atmospheric pressure (Pa) [used only for an MHK turbine cavitation check]

OpenFAST

29

Pvap

1700 Pvap - Vapour pressure of working fluid (Pa) [used only for an MHK turbine cavitation check]

OpenFAST

30

WtrDpth

50 WtrDpth - Water depth (m)

OpenFAST

31

MSL2SWL

0 MSL2SWL - Offset between still-water level and mean sea level (m) [positive upward]

AeroDyn 15

39

UAStartRad

0.25 UAStartRad - Starting radius for dynamic stall (fraction of rotor radius) [used only when AFAeroMod=2; if line is missing UAStartRad=0]

AeroDyn 15

40

UAEndRad

0.95 UAEndRad - Ending radius for dynamic stall (fraction of rotor radius) [used only when AFAeroMod=2; if line is missing UAEndRad=1]

AeroDyn driver

34

Twr2Shft

3.09343 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (m)

AirFoilTables

12*

alphaUpper

5.0 alphaUpper ! Angle of attack at upper boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data

AirFoilTables

13*

alphaLower

-3.0 alphaLower ! Angle of attack at lower boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data

AirFoilTables

42*

UACutout_delta

“DEFAULT” UACutout_delta ! Delta angle of attack below UACutout where unsteady aerodynamics begin to turn off (blend with steady solution) (deg) [Specifying the string “Default” sets UACutout_delta to 5 degrees] ! THIS IS AN OPTIONAL LINE; if omitted, it will be set to its default value

FASTFarm

28

Mod_Wake

1 Mod_Wake - Switch between wake formulations {1:Polar, 2:Curl, 3:Cartesian} (-) (switch)

FASTFarm

62

Swirl

False Swirl - Switch to include swirl velocities in wake [only used if Mod_Wake=2 or Mod_Wake=3] (-) (switch)

FASTFarm

63

k_VortexDecay

  1. k_VortexDecay - Vortex decay constant for curl (-)

FASTFarm

64

NumVortices

DEFAULT NumVortices - The number of vortices in the curled wake model (-) [DEFAULT=100]

FASTFarm

65

sigma_D

DEFAULT sigma_D - The width of the vortices in the curled wake model non-dimesionalized by rotor diameter (-) [DEFAULT=0.2]

FASTFarm

66

FilterInit

DEFAULT FilterInit - Switch to filter the initial wake plane deficit and select the number of grid points for the filter {0: no filter, 1: filter of size 1} or DEFAULT [DEFAULT=1] [unused for Mod_Wake=1] (switch)

FASTFarm

67

k_vCurl

20 k_vCurl - Calibrated parameter for scaling the eddy viscosity in the curled-wake model (-) [only used if Mod_Wake=2 or Mod_Wake=3] [>=0] or DEFAULT [DEFAULT=2.0 ]

FASTFarm

68

Mod_Projection

DEFAULT Mod_Projection - Switch to select how the wake plane velocity is project

FASTFarm

85

OutAllPlanes

True OutAllPlanes - Output all wake planes at all time steps. [DEFAULT=False]

*non-comment line count, excluding lines contained if NumCoords is not 0, and including all OPTIONAL lines in the UA coefficients table.

Modified in OpenFAST v3.1.0

Module

Line

Flag Name

Example Value

AeroDyn

16

AirDens

“default” AirDens - Air density (kg/m^3)

AeroDyn

17

KinVisc

“default” KinVisc - Kinematic viscosity of working fluid (m^2/s)

AeroDyn

18

SpdSound

“default” SpdSound - Speed of sound in air (m/s)

AeroDyn

19

Patm

“default” Patm - Atmospheric pressure (Pa) [used only when CavitCheck=True]

AeroDyn

20

Pvap

“default” Pvap - Vapour pressure of working fluid (Pa) [used only when CavitCheck=True]

HydroDyn

5

WtrDens

“default” WtrDens - Water density (kg/m^3)

HydroDyn

6

WtrDpth

“default” WtrDpth - Water depth (meters)

HydroDyn

7

MSL2SWL

“default” MSL2SWL - Offset between still-water level and mean sea level (meters) [positive upward; unused when WaveMod = 6; must be zero if PotMod=1 or 2]

Removed in OpenFAST v3.1.0

Module

Line

Flag Name

Example Value

AeroDyn

21

FluidDepth

0.5 FluidDepth - Water depth above mid-hub height (m) [used only when CavitCheck=True]

ElastoDyn

7

EnvCondSection

———————- ENVIRONMENTAL CONDITION ———————————

ElastoDyn

8

Gravity

9.80665 Gravity - Gravitational acceleration (m/s^2)

Added

Module

Line

Flag Name

Example Value

SubDyn driver

21

[separator line]

———————- LOADS ——————————————————————–

SubDyn driver

22

nAppliedLoads

1 nAppliedLoads - Number of applied loads at given nodes false

SubDyn driver

23

ALTableHeader

ALJointID Fx Fy Fz Mx My Mz UnsteadyFile

SubDyn driver

24

ALTableUnit

(-) (N) (N) (N) (Nm) (Nm) (Nm) (-)

SubDyn driver

25

ALTableLine1

10 0.0 0.0 0.0 0.0 0.0 0.0 “”

  • SubDyn: the lines at n+1 and n+2 below were inserted after line n.

Added

Module

Line

Flag Name

Example Value

SubDyn

n

OutCOSM

Output cosine matrices with the selected output member forces (flag)

SubDyn

n+1

OutCBModes

Output Guyan and Craig-Bampton modes {0: No output, 1: JSON output}, (flag)

SubDyn

n+2

OutFEMModes

Output first 30 FEM modes {0: No output, 1: JSON output} (flag)

4.1.2.9. OpenFAST v2.6.0 to OpenFAST v3.0.0

ServoDyn Changes

  • The input file parser is updated to a keyword/value pair based input. Each entry must have a corresponding keyword with the same spelling as expected.

  • The TMD submodule of ServoDyn is replaced by an updated Structural Control module (StC) with updated capabilities and input file.

Removed in OpenFAST v3.0.0

Module

Line

Flag Name

Example Value

ServoDyn

60

na

———————- TUNED MASS DAMPER —————————————

ServoDyn

61

CompNTMD

False CompNTMD - Compute nacelle tuned mass damper {true/false} (flag)

ServoDyn

62

NTMDfile

“NRELOffshrBsline5MW_ServoDyn_TMD.dat” NTMDfile - Name of the file for nacelle tuned mass damper (quoted string) [unused when CompNTMD is false]

ServoDyn

63

CompTTMD

False CompTTMD - Compute tower tuned mass damper {true/false} (flag)

ServoDyn

64

TTMDfile

“NRELOffshrBsline5MW_ServoDyn_TMD.dat” TTMDfile - Name of the file for tower tuned mass damper (quoted string) [unused when CompTTMD is false]

Added in OpenFAST v3.0.0

Module

Line

Flag Name

Example Value

ServoDyn

60

na

———————- STRUCTURAL CONTROL ————————————–

ServoDyn

61

NumBStC

0 NumBStC - Number of blade structural controllers (integer)

ServoDyn

62

BStCfiles

“unused” BStCfiles - Name of the files for blade structural controllers (quoted strings) [unused when NumBStC==0]

ServoDyn

63

NumNStC

0 NumNStC - Number of nacelle structural controllers (integer)

ServoDyn

64

NStCfiles

“unused” NStCfiles - Name of the files for nacelle structural controllers (quoted strings) [unused when NumNStC==0]

ServoDyn

65

NumTStC

0 NumTStC - Number of tower structural controllers (integer)

ServoDyn

66

TStCfiles

“unused” TStCfiles - Name of the files for tower structural controllers (quoted strings) [unused when NumTStC==0]

ServoDyn

67

NumSStC

0 NumSStC - Number of substructure structural controllers (integer)

ServoDyn

68

SStCfiles

“unused” SStCfiles - Name of the files for substructure structural controllers (quoted strings) [unused when NumSStC==0]

4.1.2.10. OpenFAST v2.5.0 to OpenFAST v2.6.0

Many changes were applied to SubDyn input file format. You may consult the following example: (SubDyn's Input File): and the online SubDyn documentation.

Added in OpenFAST v2.6.0

Module

Line

Flag Name

Example Value

AeroDyn 15

TwrTi

0.0000000E+00 6.0000000E+00 1.0000000E+00 1.0000000E-01 [additional column in Tower Influence and Aerodynamics table]

SubDyn

8

GuyanLoadCorr.

False GuyanLoadCorection - Include extra moment from lever arm at interface and rotate FEM for floating

SubDyn

15

GuyanDampMod

0 GuyanDampMod - Guyan damping {0=none, 1=Rayleigh Damping, 2=user specified 6x6 matrix}

SubDyn

16

RayleighDamp

0.001, 0.003 RayleighDamp - Mass and stiffness proportional damping coefficients (Rayleigh Damping) [only if GuyanDampMod=1]

SubDyn

17

GuyanDampSize

6 GuyanDampSize - Guyan damping matrix size (square, 6x6) [only if GuyanDampMod=2]

SubDyn

18

GuyanDampMat

0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00

SubDyn

-23

GuyanDampMat

0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00

SubDyn

na

CablesSection

————————– CABLE PROPERTIES ————————————-

SubDyn

na

CablesSection

0 NCablePropSets - Number of cable cable properties

SubDyn

na

CablesSection

PropSetID EA MatDens T0

SubDyn

na

CablesSection

(-) (N) (kg/m) (N)

SubDyn

na

RigidSection

———————- RIGID LINK PROPERTIES ————————————

SubDyn

na

RigidSection

0 NRigidPropSets - Number of rigid link properties

SubDyn

na

RigidSection

PropSetID MatDens

SubDyn

na

RigidSection

(-) (kg/m)

HydroDyn

52

NBody

1 NBody - Number of WAMIT bodies to be used (-) [>=1; only used when PotMod=1. If NBodyMod=1, the WAMIT data contains a vector of size 6*NBody x 1 and matrices of size 6*NBody x 6*NBody; if NBodyMod>1, there are NBody sets of WAMIT data each with a vector of size 6 x 1 and matrices of size 6 x 6]

HydroDyn

53

NBodyMod

1 NBodyMod - Body coupling model {1: include coupling terms between each body and NBody in HydroDyn equals NBODY in WAMIT, 2: neglect coupling terms between each body and NBODY=1 with XBODY=0 in WAMIT, 3: Neglect coupling terms between each body and NBODY=1 with XBODY=/0 in WAMIT} (switch) [only used when PotMod=1]

ServoDyn

61

NumBStC

0 NumBStC - Number of blade structural controllers (integer)

ServoDyn

62

BStCfiles

“unused” BStCfiles - Name of the files for blade structural controllers (quoted strings) [unused when NumBStC==0]

ServoDyn

63

NumNStC

0 NumNStC - Number of nacelle structural controllers (integer)

ServoDyn

64

NStCfiles

“unused” NStCfiles - Name of the files for nacelle structural controllers (quoted strings) [unused when NumNStC==0]

ServoDyn

65

NumTStC

0 NumTStC - Number of tower structural controllers (integer)

ServoDyn

66

TStCfiles

“unused” TStCfiles - Name of the files for tower structural controllers (quoted strings) [unused when NumTStC==0]

ServoDyn

67

NumSStC

0 NumSStC - Number of substructure structural controllers (integer)

ServoDyn

68

SStCfiles

“unused” SStCfiles - Name of the files for substructure structural controllers (quoted strings) [unused when NumSStC==0]

AirFoilTables

12*

alphaUpper

5.0 alphaUpper ! Angle of attack at upper boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data

AirFoilTables

13*

alphaLower

-3.0 alphaLower ! Angle of attack at lower boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data

AirFoilTables

42*

UACutout_delta

“DEFAULT” UACutout_delta ! Delta angle of attack below UACutout where unsteady aerodynamics begin to turn off (blend with steady solution) (deg) [Specifying the string “Default” sets UACutout_delta to 5 degrees] ! THIS IS AN OPTIONAL LINE; if omitted, it will be set to its default value

*non-comment line count, excluding lines contained if NumCoords is not 0, and including all OPTIONAL lines in the UA coefficients table.

Modified in OpenFAST v2.6.0

Module

Line

Flag Name

Example Value

AeroDyn 15

9

TwrShadow

0 TwrShadow - Calculate tower influence on wind based on downstream tower shadow (switch) {0=none, 1=Powles model, 2=Eames model}

SubDyn

26

Joints

JointID JointXss JointYss JointZss JointType JointDirX JointDirY JointDirZ JointStiff

SubDyn

27

Joints

(-) (m) (m) (m) (-) (-) (-) (-) (Nm/rad)

SubDyn

na

Members

MemberID MJointID1 MJointID2 MPropSetID1 MPropSetID2 MType COSMID

SubDyn

na

Members

(-) (-) (-) (-) (-) (-) (-)

SubDyn

na

ConcentratedM

CMJointID JMass JMXX JMYY JMZZ JMXY JMXZ JMYZ MCGX MCGY MCGZ

SubDyn

na

ConcentratedM

(-) (kg) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (m) (m) (m)

HydroDyn

48

ExtnMod

1 ExctnMod - Wave-excitation model {0: no wave-excitation calculation, 1: DFT, 2: state-space} (switch) [only used when PotMod=1; STATE-SPACE REQUIRES *.ssexctn INPUT FILE]

HydroDyn

49

RdtnMod

2 RdtnMod - Radiation memory-effect model {0: no memory-effect calculation, 1: convolution, 2: state-space} (switch) [only used when PotMod=1; STATE-SPACE REQUIRES *.ss INPUT FILE]

HydroDyn

50

RdtnTMax

60 RdtnTMax - Analysis time for wave radiation kernel calculations (sec) [only used when PotMod=1 and RdtnMod>0; determines RdtnDOmega=Pi/RdtnTMax in the cosine transform; MAKE SURE THIS IS LONG ENOUGH FOR THE RADIATION IMPULSE RESPONSE FUNCTIONS TO DECAY TO NEAR-ZERO FOR THE GIVEN PLATFORM!]

HydroDyn

51

RdtnDT

0.0125 RdtnDT - Time step for wave radiation kernel calculations (sec) [only used when PotMod=1 and ExctnMod>0 or RdtnMod>0; DT<=RdtnDT<=0.1 recommended; determines RdtnOmegaMax=Pi/RdtnDT in the cosine transform]

HydroDyn

54

PotFile

“Barge” PotFile - Root name of potential-flow model data; WAMIT output files containing the linear, nondimensionalized, hydrostatic restoring matrix (.hst), frequency-dependent hydrodynamic added mass matrix and damping matrix (.1), and frequency- and direction-dependent wave excitation force vector per unit wave amplitude (.3) (quoted string) [1 to NBody if NBodyMod>1] [MAKE SURE THE FREQUENCIES INHERENT IN THESE WAMIT FILES SPAN THE PHYSICALLY-SIGNIFICANT RANGE OF FREQUENCIES FOR THE GIVEN PLATFORM; THEY MUST CONTAIN THE ZERO- AND INFINITE-FREQUENCY LIMITS!]

HydroDyn

55

WAMITULEN

1 WAMITULEN - Characteristic body length scale used to redimensionalize WAMIT output (meters) [1 to NBody if NBodyMod>1] [only used when PotMod=1]

HydroDyn

56

PtfmRefxt

0.0 PtfmRefxt - The xt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1]

HydroDyn

57

PtfmRefyt

0.0 PtfmRefyt - The yt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1]

HydroDyn

58

PtfmRefzt

0.0 PtfmRefzt - The zt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1. If NBodyMod=2,PtfmRefzt=0.0]

HydroDyn

59

PtfmRefztRot

0.0 PtfmRefztRot - The rotation about zt of the body reference frame(s) from xt/yt (degrees) [1 to NBody] [only used when PotMod=1]

HydroDyn

60

PtfmVol0

6000 PtfmVol0 - Displaced volume of water when the body is in its undisplaced position (m^3) [1 to NBody] [only used when PotMod=1; USE THE SAME VALUE COMPUTED BY WAMIT AS OUTPUT IN THE .OUT FILE!]

HydroDyn

61

PtfmCOBxt

0.0 PtfmCOBxt - The xt offset of the center of buoyancy (COB) from (0,0) (meters) [1 to NBody] [only used when PotMod=1]

HydroDyn

62

PtfmCOByt

0.0 PtfmCOByt - The yt offset of the center of buoyancy (COB) from (0,0) (meters) [1 to NBody] [only used when PotMod=1]

HydroDyn

69-74

AddF0

0 AddF0 - Additional preload (N, N-m) [If NBodyMod=1, one size 6*NBody x 1 vector; if NBodyMod>1, NBody size 6 x 1 vectors]

HydroDyn

75-80

AddCLin

0 0 0 0 0 0 AddCLin - Additional linear stiffness (N/m, N/rad, N-m/m, N-m/rad) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]

HydroDyn

81-86

AddBLin

0 0 0 0 0 0 AddBLin - Additional linear damping(N/(m/s), N/(rad/s), N-m/(m/s), N-m/(rad/s)) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]

HydroDyn

87-92

AddBQuad

0 0 0 0 0 0 AddBQuad - Additional quadratic drag(N/(m/s)^2, N/(rad/s)^2, N-m(m/s)^2, N-m/(rad/s)^2) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]

HydroDyn

na

Simple Coef Tab

SimplCd SimplCdMG SimplCa SimplCaMG SimplCp SimplCpMG SimplAxCa SimplAxCaMG SimplAxCa SimplAxCaMG SimplAxCp SimplAxCpMG

HydroDyn

na

(-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)

HydroDyn

na

Depth Coef Tab

Dpth DpthCd DpthCdMG DpthCa DpthCaMG DpthCp DpthCpMG DpthAxCa DpthAxCaMG DpthAxCa DpthAxCaMG DpthAxCp DpthAxCpMG

HydroDyn

na

  1. (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)

HydroDyn

na

Member Coef Tab

MemberID MemberCd1 MemberCd2 MemberCdMG1 MemberCdMG2 MemberCa1 MemberCa2 MemberCaMG1 MemberCaMG2 MemberCp1 MemberCp2 MemberCpMG1 MemberCpMG2 MemberAxCd1 MemberAxCd2 MemberAxCdMG1 MemberAxCdMG2 MemberAxCa1 MemberAxCa2 MemberAxCaMG1 MemberAxCaMG2 MemberAxCp1 MemberAxCp2 MemberAxCpMG1 MemberAxCpMG2

HydroDyn

na

(-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)

HydroDyn

na

OutList names

see OutlistParameters.xlsx for new and revised output channel names

Removed in OpenFAST v2.6.0

Module

Line

Flag Name

Example Value

HydroDyn

68

na

———————- FLOATING PLATFORM FORCE FLAGS ————————– [unused with WaveMod=6]

HydroDyn

69

PtfmSgF

True PtfmSgF - Platform horizontal surge translation force (flag) or DEFAULT

HydroDyn

70

PtfmSwF

True PtfmSwF - Platform horizontal sway translation force (flag) or DEFAULT

HydroDyn

71

PtfmHvF

True PtfmHvF - Platform vertical heave translation force (flag) or DEFAULT

HydroDyn

72

PtfmRF

True PtfmRF - Platform roll tilt rotation force (flag) or DEFAULT

HydroDyn

73

PtfmPF

True PtfmPF - Platform pitch tilt rotation force (flag) or DEFAULT

HydroDyn

74

PtfmYF

True PtfmYF - Platform yaw rotation force (flag) or DEFAULT

4.1.2.11. OpenFAST v2.4.0 to OpenFAST v2.5.0

  • InflowWind

    • The input file parser is updated to a keyword/value pair based input. Each entry must have a corresponding keyword with the same spelling as expected. See Section 4.1.3 for an overview.

    • Driver code includes ability to convert between wind types

Added in OpenFAST v2.5.0

Module

Line

Flag Name

Example Value

IfW driver

6

[separator line]

===================== File Conversion Options =================================

IfW driver

7

WrHAWC

false WrHAWC - Convert all data to HAWC2 format? (flag)

IfW driver

8

WrBladed

false WrBladed - Convert all data to Bladed format? (flag)

IfW driver

9

WrVTK

false WrVTK - Convert all data to VTK format? (flag)

InflowWind

7

VFlowAng

0 VFlowAng - Upflow angle (degrees) (not used for native Bladed format WindType=7)

Modified in OpenFAST v2.5.0

Module

Line

Flag Name / section

Example Value

MoorDyn

na

added CtrlChan column in LINE PROPERTIES table

Renamed in OpenFAST v2.5.0

Module

Line

Previous Name

New Name

Example Value

InflowWind

17

Filename

FileName_Uni

“Shr11_30.wnd” FileName_Uni - Filename of time series data for uniform wind field. (-)

InflowWind

18

RefHt

RefHt_Uni

90 RefHt_Uni - Reference height for horizontal wind speed (m)

InflowWind

21

Filename

FileName_BTS

“unused” FileName_BTS - Name of the Full field wind file to use (.bts) (-)

InflowWind

23

Filename

FileNameRoot

“unused” FileNameRoot - WindType=4: Rootname of the full-field wind file to use (.wnd, .sum); WindType=7: name of the intermediate file with wind scaling values

InflowWind

35

RefHt

RefHt_Hawc

90 RefHt_Hawc - reference height; the height (in meters) of the vertical center of the grid (m)

InflowWind

47

PLExp

PLExp_Hawc

0.2 PLExp_Hawc - Power law exponent (-) (used for PL wind profile type only)

InflowWind

49

InitPosition(x)

XOffset

0 XOffset - Initial offset in +x direction (shift of wind box)

4.1.2.12. OpenFAST v2.3.0 to OpenFAST v2.4.0

Additional nodal output channels added for AeroDyn15, BeamDyn, and ElastoDyn.

Added in OpenFAST v2.4.0

Module

Line

Flag Name

Example Value

HydroDyn

53

ExctnMod

0 ExctnMod - Wave Excitation model {0: None, 1: DFT, 2: state-space} (-)

OpenFAST

44

CalcSteady

true CalcSteady - Calculate a steady-state periodic operating point before linearization? [unused if Linearize=False] (flag)

OpenFAST

45

TrimCase

3 TrimCase - Controller parameter to be trimmed {1:yaw; 2:torque; 3:pitch} [used only if CalcSteady=True] (-)

OpenFAST

46

TrimTol

0.0001 TrimTol - Tolerance for the rotational speed convergence [used only if CalcSteady=True] (-)

OpenFAST

47

TrimGain

0.001 TrimGain - Proportional gain for the rotational speed error (>0) [used only if CalcSteady=True] (rad/(rad/s) for yaw or pitch; Nm/(rad/s) for torque)

OpenFAST

48

Twr_Kdmp

0 Twr_Kdmp - Damping factor for the tower [used only if CalcSteady=True] (N/(m/s))

OpenFAST

49

Bld_Kdmp

0 Bld_Kdmp - Damping factor for the blades [used only if CalcSteady=True] (N/(m/s))

InflowWind

48

InitPosition(x)

0.0 InitPosition(x) - Initial offset in +x direction (shift of wind box) [Only used with WindType = 5] (m)

AeroDyn

13

CompAA

False CompAA - Flag to compute AeroAcoustics calculation [only used when WakeMod=1 or 2]

AeroDyn

14

AA_InputFile

“unused” AA_InputFile - Aeroacoustics input file

AeroDyn

35

[separator line]

====== OLAF cOnvecting LAgrangian Filaments (Free Vortex Wake) Theory Options ================== [used only when WakeMod=3]

AeroDyn

36

OLAFInputFileName

“Elliptic_OLAF.dat” OLAFInputFileName - Input file for OLAF [used only when WakeMod=3]

AirFoilTables

4*

BL_file

“unused” BL_file - The file name including the boundary layer characteristics of the profile. Ignored if the aeroacoustic module is not called.

Modified in OpenFAST v2.4.0

Module

Line

New Flag Name

Example Value

Previous Flag Name/Value

AirFoilTables

40*

filtCutOff

“DEFAULT” filtCutOff - Reduced frequency cut-off for low-pass filtering the AoA input to UA, as well as the 1st and 2nd deriv (-) [default = 0.5]

[default = 20]

*non-comment line count, excluding lines contained if NumCoords is not 0.

4.1.2.13. OpenFAST v2.2.0 to OpenFAST v2.3.0

Removed in OpenFAST v2.3.0

Module

Line

Flag Name

Example Value

AeroDyn Airfoil Input File - Airfoil Tables

2

Ctrl

0 Ctrl ! Control setting (must be 0 for current AirfoilInfo)

Added in OpenFAST v2.3.0

Module

Line

Flag Name

Example Value

AeroDyn Airfoil Input File - Airfoil Tables

2

UserProp

0 UserProp ! User property (control) setting

AeroDyn

37

AFTabMod

1 AFTabMod - Interpolation method for multiple airfoil tables {1=1D interpolation on AoA (first table only); 2=2D interpolation on AoA and Re; 3=2D interpolation on AoA and UserProp} (-)

4.1.2.14. OpenFAST v2.1.0 to OpenFAST v2.2.0

No changes required.

4.1.2.15. OpenFAST v2.0.0 to OpenFAST v2.1.0

Added in OpenFAST v2.1.0

Module

Line

Flag Name

Example Value

BeamDyn driver

21

GlbRotBladeT0

True GlbRotBladeT0 - Reference orientation for BeamDyn calculations is aligned with initial blade root?

4.1.2.16. OpenFAST v1.0.0 to OpenFAST v2.0.0

Removed in OpenFAST v2.0.0

Module

Line

Flag Name

Example Value

BeamDyn

5

analysis_type

analysis_type - 1: Static analysis; 2: Dynamic analysis

Added in OpenFAST v2.0.0

Module

Line

Flag Name

Example Value

AeroDyn

22

SkewModFactor

“default” SkewModFactor - Constant used in Pitt/Peters skewed wake model {or “default” is 15/32*pi} (-) [used only when SkewMod=2; unused when WakeMod=0]

AeroDyn

30

Section header

====== Dynamic Blade-Element/Momentum Theory Options ============================================== [used only when WakeMod=2]

AeroDyn

31

DBEMT_Mod

2 DBEMT_Mod - Type of dynamic BEMT (DBEMT) model {1=constant tau1, 2=time-dependent tau1} (-) [used only when WakeMod=2]

AeroDyn

32

tau1_const

4 tau1_const - Time constant for DBEMT (s) [used only when WakeMod=2 and DBEMT_Mod=1]

BeamDyn

5

QuasiStaticInit

True QuasiStaticInit - Use quasi-static pre-conditioning with centripetal accelerations in initialization (flag) [dynamic solve only]

BeamDyn

11

load_retries

DEFAULT load_retries - Number of factored load retries before quitting the simulation

BeamDyn

14

tngt_stf_fd

DEFAULT tngt_stf_fd - Flag to use finite differenced tangent stiffness matrix (-)

BeamDyn

15

tngt_stf_comp

DEFAULT tngt_stf_comp - Flag to compare analytical finite differenced tangent stiffness matrix (-)

BeamDyn

16

tngt_stf_pert

DEFAULT tngt_stf_pert - perturbation size for finite differencing (-)

BeamDyn

17

tngt_stf_difftol

DEFAULT tngt_stf_difftol - Maximum allowable relative difference between analytical and fd tangent stiffness (-)

BeamDyn

18

RotStates

True RotStates - Orient states in the rotating frame during linearization? (flag) [used only when linearizing]

4.1.2.17. FAST v8.16 to OpenFAST v1.0.0

The transition from FAST v8 to OpenFAST is described in detail at FAST v8 and the transition to OpenFAST.

Removed in OpenFAST v1.0.0

Module

Line

Flag Name

Example Value

OpenFAST

18

CompSub

0 CompSub - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn}

Added in OpenFAST v1.0.0

Module

Line

Flag Name

Example Value

OpenFAST

18

CompSub

0 CompSub - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn; 2=External Platform MCKF}

AeroDyn

12

CavityCheck

False CavitCheck - Perform cavitation check? (flag)

AeroDyn

17

Patm

9999.9 Patm - Atmospheric pressure (Pa) [used only when CavitCheck=True]

AeroDyn

18

Pvap

9999.9 Pvap - Vapor pressure of fluid (Pa) [used only when CavitCheck=True]

AeroDyn

19

FluidDepth

9999.9 FluidDepth - Water depth above mid-hub height (m) [used only when CavitCheck=True]