Analysis Options Inputs

The following inputs describe the options available in the analysis_options file. This example is from the 03_blade case in the examples directory.

general:
    folder_output: outputs_aerostruct
    fname_output: blade_out

design_variables:
    rotor_diameter:
        flag: True
        minimum: 190
        maximum: 240
    blade:
        aero_shape:
            twist:
                flag: True             # Flag to optimize the twist
                inverse: False         # Flag to determine twist from the user-defined desired margin to stall (defined in constraints)
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.08722222222222221 # Maximum decrease for the twist in [rad] at the n_opt locations
                max_increase: 0.08722222222222221 # Maximum increase for the twist in [rad] at the n_opt locations
                index_start: 2         # Lock the first two DVs from blade root
                index_end: 4           # All DVs close to blade tip are active
            chord:
                flag: True             # Flag to optimize the chord
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.3      # Minimum multiplicative gain on existing chord at the n_opt locations
                max_increase: 3.       # Maximum multiplicative gain on existing chord at the n_opt locations
                index_start: 2         # Lock the first two DVs from blade root
                index_end: 4           # All DVs close to blade tip are active
        structure:
            spar_cap_ss:
                flag: True             # Flag to optimize the spar cap thickness on the suction side
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.7      # Maximum nondimensional decrease at the n_opt locations
                max_increase: 1.3      # Maximum nondimensional increase at the n_opt locations
                index_start: 1         # Lock the first DV from blade root
                index_end: 3           # The last DV at blade tip is locked
            spar_cap_ps:
                flag: True             # Flag to optimize the spar cap thickness on the pressure side
                equal_to_suction: True # Flag to impose the spar cap thickness on pressure and suction sides equal
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.7      # Maximum nondimensional decrease at the n_opt locations
                max_increase: 1.3      # Maximum nondimensional increase at the n_opt locations
                index_start: 1         # Lock the first DV from blade root
                index_end: 3           # The last DV at blade tip is locked
            te_ss:
                flag: False            # Flag to optimize the spar cap thickness on the suction side
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.7      # Maximum nondimensional decrease at the n_opt locations
                max_increase: 1.3      # Maximum nondimensional increase at the n_opt locations
                index_start: 1         # Lock the first DV from blade root
                index_end: 3           # The last DV at blade tip is locked
            te_ps:
                flag: False            # Flag to optimize the spar cap thickness on the pressure side
                n_opt: 4               # Number of control points along blade span
                max_decrease: 0.7      # Maximum nondimensional decrease at the n_opt locations
                max_increase: 1.3      # Maximum nondimensional increase at the n_opt locations
                index_start: 1         # Lock the first DV from blade root
                index_end: 3           # The last DV at blade tip is locked

merit_figure: LCOE

constraints:
    blade:
        strains_spar_cap_ss:
            flag: True         # Flag to impose constraints on maximum strains (absolute value) in the spar cap on the blade suction side
            max:    3500.e-6   # Value of maximum strains [-]
            index_start: 1     # Do not enforce constraint at the first station from blade root of the n_opt from spar_cap_ss
            index_end: 3       # Do not enforce constraint at the last station at blade tip of the n_opt from spar_cap_ss
        strains_spar_cap_ps:
            flag: True         # Flag to impose constraints on maximum strains (absolute value) in the spar cap on the blade pressure side
            max:    3500.e-6   # Value of maximum strains [-]
            index_start: 1     # Do not enforce constraint at the first station from blade root of the n_opt from spar_cap_ps
            index_end: 3       # Do not enforce constraint at the last station at blade tip of the n_opt from spar_cap_ps
        strains_te_ss:
            flag: False        # Flag to impose constraints on maximum strains (absolute value) in the spar cap on the blade suction side
            max:    3500.e-6   # Value of maximum strains [-]
            index_start: 1     # Do not enforce constraint at the first station from blade root of the n_opt from spar_cap_ss
            index_end: 3       # Do not enforce constraint at the last station at blade tip of the n_opt from spar_cap_ss
        strains_te_ps:
            flag: False        # Flag to impose constraints on maximum strains (absolute value) in the spar cap on the blade pressure side
            max:    3500.e-6   # Value of maximum strains [-]
            index_start: 1     # Do not enforce constraint at the first station from blade root of the n_opt from spar_cap_ps
            index_end: 3       # Do not enforce constraint at the last station at blade tip of the n_opt from spar_cap_ps
        tip_deflection:
            flag: True
            margin: 1.4175
        stall:
            flag: True    # Constraint on minimum stall margin
            margin: 0.087 # Value of minimum stall margin in [rad]

driver:
    optimization:
        flag: True         # Flag to enable optimization
        tol: 1.e-5          # Optimality tolerance
        # max_major_iter: 10  # Maximum number of major design iterations (SNOPT)
        # max_minor_iter: 100 # Maximum number of minor design iterations (SNOPT)
        max_iter: 1         # Maximum number of iterations (SLSQP)
        solver: SLSQP       # Optimization solver. Other options are 'SLSQP' - 'CONMIN'
        step_size: 1.e-3    # Step size for finite differencing
        form: forward       # Finite differencing mode, either forward or central

recorder:
    flag: False             # Flag to activate OpenMDAO recorder
    file_name: log_opt.sql # Name of OpenMDAO recorder

general

folder_outputString

Name of folder to dump output files

Default = output

fname_outputString

File prefix for output files

Default = output

design_variables

Sets the design variables in a design optimization and analysis

rotor_diameter

Adjust the rotor diameter by changing the blade length (all blade properties constant with respect to non-dimensional span coordinates)

flagBoolean

Activates as a design variable or constraint

Default = False

minimum : Float, m

Default = 0.0

Minimum = 0.0 Maximum = 1000.0

maximum : Float, m

Default = 0.0

Minimum = 0.0 Maximum = 1000.0

blade

Design variables associated with the wind turbine blades

aero_shape

Design variables associated with the blade aerodynamic shape

twist

Blade twist as a design variable by adding or subtracting radians from the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

inverseBoolean

When set to True, the twist is defined inverting the blade-element momentum equations to achieve a desired margin to stall, which is defined among the constraints. flag and inverse cannot be simultaneously be set to True

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the twist distribution along blade span.

Default = 8

Minimum = 4

lower_boundArray of Floats, rad

Lowest number of radians that can be added (typically negative to explore smaller twist angles)

Default = [-0.1, -0.1, -0.1, -0.1, -0.1, -0.1, -0.1, -0.1]

upper_boundArray of Floats, rad

Largest number of radians that can be added (typically postive to explore greater twist angles)

Default = [0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1]

index_startInteger

Integer setting the first DV of the n_opt along span that is optimized. It is recommended to set index_start to 1 to lock the first DV and prevent the optimizer to try to optimize the twist of the blade root cylinder.

Default = 0

index_endInteger

Integer setting the last DV of the n_opt along span that is optimized.

Default = 8

chord

Blade chord as a design variable by scaling (multiplying) the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the chord distribution along blade span.

Default = 8

Minimum = 4

max_decreaseFloat

Maximum nondimensional decrease of the blade chord at each optimization location

Default = 0.5

max_increaseFloat

Maximum nondimensional increase of the blade chord at each optimization location

Default = 1.5

index_startInteger

Integer setting the first DV of the n_opt along span that is optimized. Setting index_start to 1 or 2 locks the blade root diameter.

Default = 0

index_endInteger

Integer setting the last DV of the n_opt along span that is optimized. It is recommended to lock the last point close to blade tip, setting index_end to n_opt minus 1. The last point controls the chord length at blade tip and due to the imperfect tip loss models of CCBlade, it is usually a good idea to taper the chord manually and do not let a numerical optimizer control it.

Default = 8

af_positions

Adjust airfoil positions along the blade span.

flagBoolean

Activates as a design variable or constraint

Default = False

af_startInteger

Index of airfoil where the optimization can start shifting airfoil position. The airfoil at blade tip is always locked. It is advised to keep the airfoils close to blade root locked.

Default = 4

Minimum = 1

structure

Design variables associated with the internal blade structure

spar_cap_ss

Blade suction-side spar cap thickness as a design variable by scaling (multiplying) the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the thickness of the spar cap on the suction side.

Default = 8

Minimum = 4

max_decreaseFloat

Maximum nondimensional decrease of the spar cap thickness on the suction-side at each optimization location

Default = 0.5

max_increaseFloat

Maximum nondimensional increase of the spar cap thickness on the suction-side at each optimization location

Default = 1.5

index_startInteger

Integer setting the first DV of the n_opt along span that is optimized. It is recommended to set index_start to 1 to lock the first DV and impose a pre- defined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 0

index_endInteger

Integer setting the last DV of the n_opt along span that is optimized. It is recommended to lock the last point close to blade tip, setting index_end to n_opt minus 1. This imposes a predefined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 8

spar_cap_ps

Blade pressure-side spar cap thickness as a design variable by scaling (multiplying) the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the thickness of the spar cap on the pressure side.

Default = 8

Minimum = 4

max_decreaseFloat

Maximum nondimensional decrease of the spar cap thickness on the pressure-side at each optimization location

Default = 0.5

max_increaseFloat

Maximum nondimensional increase of the spar cap thickness on the pressure-side at each optimization location

Default = 1.5

index_startInteger

Integer setting the first DV of the n_opt along span that is optimized. It is recommended to set index_start to 1 to lock the first DV and impose a pre- defined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 0

index_endInteger

Integer setting the last DV of the n_opt along span that is optimized. It is recommended to lock the last point close to blade tip, setting index_end to n_opt minus 1. This imposes a predefined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 8

te_ss

Blade suction-side trailing edge reinforcement thickness as a design variable by scaling (multiplying) the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the thickness of the trailing edge reinforcement on the suction side. By default, the first point close to blade root and the last point close to blade tip are locked. This is done to impose a pre-defined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 8

Minimum = 4

min_gainFloat

Lower bound on scalar multiplier that will be applied to value at control points

Default = 0.5

max_gainFloat

Upper bound on scalar multiplier that will be applied to value at control points

Default = 1.5

te_ps

Blade pressure-side trailing edge reinforcement thickness as a design variable by scaling (multiplying) the initial value at spline control points along the span.

flagBoolean

Activates as a design variable or constraint

Default = False

n_optInteger

Number of equally-spaced control points of the spline parametrizing the thickness of the trailing edge reinforcement on the pressure side. By default, the first point close to blade root and the last point close to blade tip are locked. This is done to impose a pre-defined taper to small thicknesses and mimic a blade manufacturability constraint.

Default = 8

Minimum = 4

min_gainFloat

Lower bound on scalar multiplier that will be applied to value at control points

Default = 0.5

max_gainFloat

Upper bound on scalar multiplier that will be applied to value at control points

Default = 1.5

control

Design variables associated with the control of the wind turbine

tsr

Adjust the tip-speed ratio (ratio between blade tip velocity and steady hub-height wind speed)

flagBoolean

Activates as a design variable or constraint

Default = False

minimumFloat

Minimum allowable value

Default = 0.0

Minimum = 0.0 Maximum = 30.0

maximumFloat

Maximum allowable value

Default = 0.0

Minimum = 0.0 Maximum = 30.0

hub

Design variables associated with the hub

cone

Adjust the blade attachment coning angle (positive values are always away from the tower whether upwind or downwind)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, rad

Design variable bound

Default = 0.0

Minimum = 0.0 Maximum = 0.5235987756

upper_boundFloat, rad

Design variable bound

Default = 0.0

Minimum = 0.0 Maximum = 0.5235987756

hub_diameter

Adjust the rotor hub diameter

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for hub diameter

Default = 0.0

Minimum = 0.0 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for hub diameter

Default = 30.0

Minimum = 0.0 Maximum = 30.0

drivetrain

Design variables associated with the drivetrain

uptilt

Adjust the drive shaft tilt angle (positive values tilt away from the tower whether upwind or downwind)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, rad

Design variable bound

Default = 0.0

Minimum = 0.0 Maximum = 0.5235987756

upper_boundFloat, rad

Design variable bound

Default = 0.0

Minimum = 0.0 Maximum = 0.5235987756

overhang

Adjust the x-distance, parallel to the ground or still water line, from the tower top center to the rotor apex.

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

distance_tt_hub

Adjust the z-dimension height from the tower top to the rotor apex

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

distance_hub_mb

Adjust the distance along the drive staft from the hub flange to the first main bearing

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

distance_mb_mb

Adjust the distance along the drive staft from the first to the second main bearing

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

generator_length

Adjust the distance along the drive staft between the generator rotor drive shaft attachment to the stator bedplate attachment

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

gear_ratio

For geared configurations only, adjust the gear ratio of the gearbox that multiplies the shaft speed and divides the torque

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float

Default = 1.0

Minimum = 1.0 Maximum = 500.0

upper_bound : Float

Default = 150.0

Minimum = 1.0 Maximum = 1000.0

lss_diameter

Adjust the diameter at the beginning and end of the low speed shaft (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

hss_diameter

Adjust the diameter at the beginning and end of the high speed shaft (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

nose_diameter

For direct-drive configurations only, adjust the diameter at the beginning and end of the nose/turret (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Lowest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

upper_boundFloat, m

Highest value allowable for design variable

Default = 0.1

Minimum = 0.1 Maximum = 30.0

lss_wall_thickness

Adjust the thickness at the beginning and end of the low speed shaft (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

hss_wall_thickness

Adjust the thickness at the beginning and end of the high speed shaft (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

nose_wall_thickness

For direct-drive configurations only, adjust the thickness at the beginning and end of the nose/turret (assumes a linear taper)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

bedplate_wall_thickness

For direct-drive configurations only, adjust the wall thickness along the elliptical bedplate

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

bedplate_web_thickness

For geared configurations only, adjust the I-beam web thickness of the bedplate

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

bedplate_flange_thickness

For geared configurations only, adjust the I-beam flange thickness of the bedplate

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

bedplate_flange_width

For geared configurations only, adjust the I-beam flange width of the bedplate

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.001

Minimum = 0.001 Maximum = 3.0

upper_bound : Float, m

Default = 1.0

Minimum = 0.01 Maximum = 5.0

tower

Design variables associated with the tower or monopile

outer_diameter

Adjust the outer diamter of the cylindrical column at nodes along the height. Linear tapering is assumed between the nodes, creating conical frustums in each section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

upper_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

layer_thickness

Adjust the layer thickness of each section in the column

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 0.01

Minimum = 1e-05 Maximum = 1.0

upper_boundFloat, m

Design variable bound

Default = 0.01

Minimum = 1e-05 Maximum = 1.0

section_height

Adjust the height of each conical section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

upper_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

monopile

Design variables associated with the tower or monopile

outer_diameter

Adjust the outer diamter of the cylindrical column at nodes along the height. Linear tapering is assumed between the nodes, creating conical frustums in each section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

upper_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

layer_thickness

Adjust the layer thickness of each section in the column

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 0.01

Minimum = 1e-05 Maximum = 1.0

upper_boundFloat, m

Design variable bound

Default = 0.01

Minimum = 1e-05 Maximum = 1.0

section_height

Adjust the height of each conical section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

upper_boundFloat, m

Design variable bound

Default = 5.0

Minimum = 0.1 Maximum = 100.0

constraints

Activate the constraints that are applied to a design optimization

blade

Constraints associated with the blade design

strains_spar_cap_ss

Enforce a maximum allowable strain in the suction-side spar caps

flagBoolean

Activates as a design variable or constraint

Default = False

maxFloat

Maximum allowable strain value

Default = 0.004

Minimum = 1e-08 Maximum = 0.1

strains_spar_cap_ps

Enforce a maximum allowable strain in the pressure-side spar caps

flagBoolean

Activates as a design variable or constraint

Default = False

maxFloat

Maximum allowable strain value

Default = 0.004

Minimum = 1e-08 Maximum = 0.1

tip_deflection

Enforce a maximum allowable blade tip deflection towards the tower expressed as a safety factor on the parked margin. Meaning a parked distance to the tower of 30m and a constraint value here of 1.5 would mean that 30/1.5=20m of deflection is the maximum allowable

flagBoolean

Activates as a design variable or constraint

Default = False

margin : Float

Default = 1.4175

Minimum = 1.0 Maximum = 10.0

rail_transport

Enforce sufficient blade flexibility such that they can be transported on rail cars without exceeding maximum blade strains or derailment. User can activate either 8-axle flatcars or 4-axle

8_axleBoolean

Activates as a design variable or constraint

Default = False

4_axleBoolean

Activates as a design variable or constraint

Default = False

stall

Ensuring blade angles of attacks do not approach the stall point. Margin is expressed in radians from stall.

flagBoolean

Activates as a design variable or constraint

Default = False

margin : Float, radians

Default = 0.05233

Minimum = 0.0 Maximum = 0.5

chord

Enforcing max chord length limit at all points along blade span.

flagBoolean

Activates as a design variable or constraint

Default = False

max : Float, meter

Default = 4.3

Minimum = 0.1 Maximum = 20.0

root_circle_diameter

Enforcing the minimum blade root circle diameter.

flagBoolean

Activates as a design variable or constraint

Default = False

frequency

Frequency separation constraint between blade fundamental frequency and blade passing (3P) frequency at rated conditions using gamma_freq margin. Can be activated for blade flap and/or edge modes.

flap_3PBoolean

Activates as a design variable or constraint

Default = False

edge_3PBoolean

Activates as a design variable or constraint

Default = False

moment_coefficient

(EXPERIMENTAL) Targeted blade moment coefficient (useful for managing root flap loads or inverse design approaches that is not recommendend for general use)

flagBoolean

Activates as a design variable or constraint

Default = False

min : Float

Default = 0.15

Minimum = 0.01 Maximum = 5.0

max : Float

Default = 0.15

Minimum = 0.01 Maximum = 5.0

match_cl_cd

(EXPERIMENTAL) Targeted airfoil cl/cd ratio (useful for inverse design approaches that is not recommendend for general use)

flag_clBoolean

Activates as a design variable or constraint

Default = False

flag_cdBoolean

Activates as a design variable or constraint

Default = False

filenameString

file path to constraint data

Default =

match_L_D

(EXPERIMENTAL) Targeted blade moment coefficient (useful for managing root flap loads or inverse design approaches that is not recommendend for general use)

flag_LBoolean

Activates as a design variable or constraint

Default = False

flag_DBoolean

Activates as a design variable or constraint

Default = False

filenameString

file path to constraint data

Default =

tower

Constraints associated with the tower design

height_constraint

Double-sided constraint to ensure total tower height meets target hub height when adjusting section heights

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.01

Minimum = 1e-06 Maximum = 10.0

upper_bound : Float, m

Default = 0.01

Minimum = 1e-06 Maximum = 10.0

stress

Enforce a maximum allowable von Mises stress relative to the material yield stress with safety factor of gamma_f * gamma_m * gamma_n

flagBoolean

Activates as a design variable or constraint

Default = False

global_buckling

Enforce a global buckling limit using Eurocode checks with safety factor of gamma_f * gamma_b

flagBoolean

Activates as a design variable or constraint

Default = False

shell_buckling

Enforce a shell buckling limit using Eurocode checks with safety factor of gamma_f * gamma_b

flagBoolean

Activates as a design variable or constraint

Default = False

slope

Ensure that the diameter moving up the tower at any node is always equal or less than the diameter of the node preceding it

flagBoolean

Activates as a design variable or constraint

Default = False

d_to_t

Double-sided constraint to ensure target diameter to thickness ratio for manufacturing and structural objectives

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float

Default = 50.0

Minimum = 1.0 Maximum = 2000.0

upper_bound : Float

Default = 50.0

Minimum = 1.0 Maximum = 2000.0

taper

Enforcing a max allowable conical frustum taper ratio per section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float

Default = 0.5

Minimum = 0.001 Maximum = 1.0

frequency

Frequency separation constraint between all tower modal frequencies and blade period (1P) and passing (3P) frequencies at rated conditions using gamma_freq margin.

flagBoolean

Activates as a design variable or constraint

Default = False

frequency_1

Targeted range for tower first frequency constraint. Since first and second frequencies are generally the same for the tower, this usually governs the second frequency as well (both fore-aft and side-side first frequency)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, Hz

Default = 0.1

Minimum = 0.01 Maximum = 1.0

upper_bound : Float, Hz

Default = 0.1

Minimum = 0.01 Maximum = 1.0

monopile

Constraints associated with the monopile design

pile_depth

Ensures that the submerged suction pile depth meets a minimum value

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, m

Default = 0.0

Minimum = 0.0 Maximum = 200.0

stress

Enforce a maximum allowable von Mises stress relative to the material yield stress with safety factor of gamma_f * gamma_m * gamma_n

flagBoolean

Activates as a design variable or constraint

Default = False

global_buckling

Enforce a global buckling limit using Eurocode checks with safety factor of gamma_f * gamma_b

flagBoolean

Activates as a design variable or constraint

Default = False

shell_buckling

Enforce a shell buckling limit using Eurocode checks with safety factor of gamma_f * gamma_b

flagBoolean

Activates as a design variable or constraint

Default = False

slope

Ensure that the diameter moving up the tower at any node is always equal or less than the diameter of the node preceding it

flagBoolean

Activates as a design variable or constraint

Default = False

d_to_t

Double-sided constraint to ensure target diameter to thickness ratio for manufacturing and structural objectives

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float

Default = 50.0

Minimum = 1.0 Maximum = 2000.0

upper_bound : Float

Default = 50.0

Minimum = 1.0 Maximum = 2000.0

taper

Enforcing a max allowable conical frustum taper ratio per section

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float

Default = 0.5

Minimum = 0.001 Maximum = 1.0

frequency

Frequency separation constraint between all tower modal frequencies and blade period (1P) and passing (3P) frequencies at rated conditions using gamma_freq margin.

flagBoolean

Activates as a design variable or constraint

Default = False

frequency_1

Targeted range for tower first frequency constraint. Since first and second frequencies are generally the same for the tower, this usually governs the second frequency as well (both fore-aft and side-side first frequency)

flagBoolean

Activates as a design variable or constraint

Default = False

lower_bound : Float, Hz

Default = 0.1

Minimum = 0.01 Maximum = 1.0

upper_bound : Float, Hz

Default = 0.1

Minimum = 0.01 Maximum = 1.0

hub

hub_diameter

Ensure that the diameter of the hub is sufficient to accommodate the number of blades and blade root diameter

flagBoolean

Activates as a design variable or constraint

Default = False

drivetrain

lss

Enforce a maximum allowable von Mises stress relative to the material yield stress with safety factor of gamma_f * gamma_m * gamma_n

flagBoolean

Activates as a design variable or constraint

Default = False

hss

Enforce a maximum allowable von Mises stress relative to the material yield stress with safety factor of gamma_f * gamma_m * gamma_n

flagBoolean

Activates as a design variable or constraint

Default = False

bedplate

Enforce a maximum allowable von Mises stress relative to the material yield stress with safety factor of gamma_f * gamma_m * gamma_n

flagBoolean

Activates as a design variable or constraint

Default = False

mb1

Ensure that the angular deflection at this meain bearing does not exceed the maximum allowable deflection for the bearing type

flagBoolean

Activates as a design variable or constraint

Default = False

mb2

Ensure that the angular deflection at this meain bearing does not exceed the maximum allowable deflection for the bearing type

flagBoolean

Activates as a design variable or constraint

Default = False

length

Ensure that the bedplate length is sufficient to meet desired overhang value

flagBoolean

Activates as a design variable or constraint

Default = False

height

Ensure that the bedplate height is sufficient to meet desired nacelle height value

flagBoolean

Activates as a design variable or constraint

Default = False

access

For direct-drive configurations only, ensure that the inner diameter of the nose/turret is big enough to allow human access

flagBoolean

Activates as a design variable or constraint

Default = False

lower_boundFloat, meter

Minimum size to ensure human maintenance access

Default = 2.0

Minimum = 0.1 Maximum = 5.0

ecc

For direct-drive configurations only, ensure that the elliptical bedplate length is greater than its height

flagBoolean

Activates as a design variable or constraint

Default = False

merit_figureString from, [‘LCOE’, ‘AEP’, ‘Cp’, ‘blade_mass’, ‘tower_mass’, ‘tower_cost’, ‘monopile_mass’, ‘monopile_cost’, ‘structural_mass’, ‘structural_cost’, ‘blade_tip_deflection’, ‘My_std’, ‘flp1_std’]

Objective function / merit figure for optimization. Choices are LCOE- levelized cost of energy, AEP- turbine annual energy production, Cp- rotor power coefficient, blade_mass, tower_mass, tower_cost, monopile_mass, monopile_cost, structural_mass- tower+monopile mass, structural_cost- tower+monopile cost, blade_tip_deflection- blade tip deflection distance towards tower, My_std- blade flap moment standard deviation, flp1_std- trailing flap standard deviation

Default = LCOE

driver

Specification of the optimization driver (optimization algorithm) parameters

tolFloat

Convergence tolerance (relative)

Default = 1e-06

Minimum = 1e-12 Maximum = 1.0

max_iterInteger

Max number of optimization iterations

Default = 100

Minimum = 0 Maximum = 100000

max_function_callsInteger

Max number of calls to objective function evaluation

Default = 100000

Minimum = 0 Maximum = 100000000

solverString from, [‘SLSQP’, ‘CONMIN’, ‘COBYLA’, ‘SNOPT’]

Optimization driver. Can be one of [SLSQP, CONMIN, COBYLA, SNOPT]

Default = SLSQP

step_sizeFloat

Maximum step size

Default = 0.001

Minimum = 1e-10 Maximum = 100.0

formString from, [‘central’, ‘forward’, ‘complex’]

Finite difference calculation mode

Default = central

recorder

Optimization iteration recording via OpenMDAO

flagBoolean

Activates as a design variable or constraint

Default = False

file_nameString

OpenMDAO recorder output SQL database file

Default = log_opt.sql