Parameter Table

This page is intended to list all of the parameters and a short description of each one.

general

This section contains options that apply to the run as a whole, where files are stored, the type of study, etc.

Name	Type	Units	Default	Description
name	[‘string’, ‘null’]	-	None	The folder name for the current run.
preappend_datetime	boolean	-	False	If true, the time and date will be preappened to the output folder.
output	array	-	[‘solution’]	These are the fields that can be saved during/after the simulation, one of mesh, initial_guess, height, turbine_force, solution, and debug.
output_folder	string	-	output/	This is the root folder for all the output files.
output_type	string	-	pvd	This is the filetype various fields are saved in, choices pvd, xdmf (note xdmf is better for parallel, but pvd can be opened during simulation).
dolfin_adjoint	boolean	-	False	If true, this will import dolfin_adjoint which is required for calculating gradients. Must be true for optimizations.
debug_mode	boolean	-	False	If true, a file, tagged_output.yaml, is created in the root output folder. Used for unit and regression tests.

domain

Here we set the properties of the computational domain, what shape it is, whether there is terrain present, how to discretize across dimensions, and how to generate the mesh.

Name	Type	Units	Default	Description
type	[‘string’, ‘null’]	-	None	The type of domain, options are rectangle, box, cylinder, circle, imported, or interpolated. See Formatting for Importing a Domain
path	[‘string’, ‘null’]	-	None	The path to all domain files if using imported domain and standard naming.
mesh_path	[‘string’, ‘null’]	-	None	A specific path for the imported mesh file.
terrain_path	[‘string’, ‘null’]	-	None	A specific path for the terrain file if using complex/interpolated terrain.
bound_path	[‘string’, ‘null’]	-	None	A specific path to a MeshFunction file that stores the boundary IDs.
filetype	string	-	xml.gz	The file type for imported domains, options are xml, xml.gz, or h5.
scaled	boolean	-	False	Attempt scale the domain to km instead of m. (Extremely experimental, do not use).
ground_reference	number	meter	0.0	The z-coordinate of the ground.
streamwise_periodic	boolean	-	False	Sets periodic boundary conditions along the x-direction (Not yet implemented).
spanwise_periodic	boolean	-	False	Sets periodic boundary conditions along the y-direction (Not yet implemented).
x_range	[‘array’, ‘null’]	meter	None	The range of the domain in the streamwise direction, e.g., [x_min, x_max].
y_range	[‘array’, ‘null’]	meter	None	The range of the domain in the spanwise direction, e.g., [y_min, y_max].
z_range	[‘array’, ‘null’]	meter	None	The range of the domain in the vertical direction, e.g., [z_min, z_max].
nx	[‘integer’, ‘null’]	dimensionless	None	The integer number of nodes in the streamwise (x) direction.
ny	[‘integer’, ‘null’]	dimensionless	None	The integer number of nodes in the spanwise (y) direction.
nz	[‘integer’, ‘null’]	dimensionless	None	The integer number of nodes in the vertical (z) direction.
mesh_type	string	-	mshr	Sets how the cylinder/circle domains are meshed, options are mshr, elliptic, squircular, or stretch.
center	[‘array’, ‘null’]	meter	None	Center of the cylinder/circle domains, e.g., [x_center, y_center].
radius	[‘number’, ‘null’]	meter	None	Radius for the cylinder/circle domains.
nt	[‘integer’, ‘null’]	dimensionless	None	Integer number of nodes in the theta direction for cylinder/circle domains.
res	[‘number’, ‘null’]	meter	None	The characteristic cell length for cylinder/circle domains generated with the mshr mesh_type.
interpolated	boolean	-	False	Lets you define a terrain_path to have complex domain.
analytic	boolean	-	False	Use an analytic function instead of a terrain_path.
gaussian				Create a gaussian hill analytic complex terrain.
|--gaussian:center	[‘array’, ‘null’]	meter	[0.0, 0.0]	Center of the hill.
|--gaussian:theta	number	radians	0.0	Rotation of the hill.
|--gaussian:amp	[‘number’, ‘null’]	meter	None	Height of the hill.
|--gaussian:sigma_x	[‘number’, ‘null’]	meter	None	Skew in x.
|--gaussian:sigma_y	[‘number’, ‘null’]	meter	None	Skew in y.
plane				Create a plane analytic complex terrain.
|--plane:intercept	array	meter	[0.0, 0.0, 0.0]	Define a plane with z = mx(x-x0)+my(y-y0)+z0, where intercept = [x0, y0, z0]
|--plane:mx	[‘number’, ‘null’]	meter/meter	None	x slope.
|--plane:my	[‘number’, ‘null’]	meter/meter	None	y slope.

wind_farm

Assign the values for the wind farm, where it resides in the computational domain, how many turbines, and the turbines’ layout and arrangement.

Name	Type	Units	Default	Description
type	[‘string’, ‘null’]	-	None	Type of wind farm, options are grid, random, imported, or empty. See Formatting for Importing a Wind Farm
path	[‘string’, ‘null’]	-	None	Location of imported wind farm.
display	boolean	-	False	If true, then use matplotlib and show() the wind farm/chord profiles mid run.
ex_x	[‘array’, ‘null’]	meter	None	Extents of the farm in the x direction, e.g., [x_min, x_max].
ex_y	[‘array’, ‘null’]	meter	None	Extents of the farm in the y direction, e.g., [y_min, y_max].
x_spacing	[‘number’, ‘null’]	meter	None	x spacing between turbines.
y_spacing	[‘number’, ‘null’]	meter	None	y spacing between turbines.
x_shear	[‘number’, ‘null’]	meter	None	x offset between rows.
y_shear	[‘number’, ‘null’]	meter	None	y offset between columns.
min_sep_dist	number	meter	2	The minimum separation distance for a random farm, expressed in units of rotor diameter, e.g., a value of 2 means a min_sep_dist of 2*RD.
grid_rows	[‘integer’, ‘null’]	dimensionless	None	Integer number of turbines in the y direction.
grid_cols	[‘integer’, ‘null’]	dimensionless	None	Integer number of turbines in the x direction.
jitter	[‘number’, ‘boolean’]	meter	0.0	Magnitude of random noise added to a gridded wind farm.
numturbs	[‘integer’, ‘null’]	dimensionless	None	Total integer number of turbines.
seed	[‘integer’, ‘null’]	dimensionless	None	Seed to control/prescribe the randomness between runs.

turbines

The properties of the turbines themselves, in contrast to wind_farm, these are principally variables that define turbine-level properties, e.g., how the force is modeled and how the turbines are operated.

Name	Type	Units	Default	Description
type	[‘string’, ‘null’]	-	None	Type of representation, options are 2D_disk, numpy_disk, disk, hybrid_disk, line, expr_disk, dolfin_line, or disabled. See Supported Turbine Representation
HH	[‘number’, ‘null’]	meter	None	Hub height.
RD	[‘number’, ‘null’]	meter	None	Rotor diameter.
thickness	[‘number’, ‘null’]	meter	None	Thickness of the actuator disk (usually 10% of RD).
yaw	[‘number’, ‘null’]	radians	None	Yaw of the turbine relative to inflow angle.
axial	[‘number’, ‘null’]	dimensionless	None	Axial induction value for actuator disks.
force	string	-	sine	Distribution of force along the radial direction of an actuator disk, options are constant, sine, or chord.
rpm	[‘number’, ‘null’]	rotations/minute	None	Rotation specified for the alm method.
read_turb_data	[‘string’, ‘null’]	-	None	Path to alm data.
blade_segments	[‘string’, ‘integer’]	dimensionless	computed	Integer number of nodes along the rotor radius.
use_local_velocity	boolean	-	True	Use the velocity measured in the rotor plane to compute alm forces (otherwise use inflow).
max_chord	number	meter	1000	Upper limit when optimizing chord.
chord_factor	number	dimensionless	1.0	This multiplies all the chords by a constant factor, e.g., 2.0 makes a chord that is twice as thick everywhere.
gauss_factor	number	dimensionless	2.0	This is the factor that gets multiplied by the minimum mesh spacing to set the gaussian width, e.g., gaussian_width = 2.0*dx_min.
tip_loss	boolean	-	True	Determines whether or not a tip-loss model is used in the calculation of the ALM force (False means no tip loss is modeled).
hub_rad	number	meter	0.0	The radius of the hub. If non-zero, actuator nodes will still be placed in the full range [0, rotor_radius], but the lift/drag properties in the range [0, hub_rad] will be modified to reflect the blade root.
chord_perturb	number	meter	0.0	An amount to perturb one of the chord values, used for finite difference gradient calculations.
chord_perturb_id	integer	dimensionless	0	The integer index of the chord to perturb, used for finite difference gradient calculations.
chord_override	[‘string’, ‘null’]	-	None	The path to a specific chord to use in CSV format, e.g., input_data/chord_base.csv.
motion_file	[‘string’, ‘null’]	-	None	Location to the platform motion data.
motion_type	[‘array’, ‘string’, ‘null’]	-	None	Type of motion to apply can be single string or list of: ‘surge’, ‘sway’, ‘heave’, ‘roll’, ‘pitch’, and/or ‘yaw’.
use_gauss_vel_probe	boolean	-	False	Probe velocity at ALM nodes using an gaussian sphere rather than the eval() function.
use_ap_linear_interp	boolean	-	False	Uses linear interpolation when building the airfoil polars.

refine

A set of options to control how the original mesh is refined, e.g., across the entire farm extent, locally around turbines, or combinations of options. See Mesh Refinement Options

Name	Type	Units	Default	Description
warp_type	[‘string’, ‘null’]	-	None	Warping will shift the nodes along the z direction concentrating them near the ground, options are smooth or split.
warp_strength	[‘number’, ‘null’]	dimensionless	None	For smooth warps, how aggressively they are moved to the ground.
warp_percent	[‘number’, ‘null’]	dimensionless	None	For split warps, percentage moved below the warp_heigth.
warp_height	[‘number’, ‘null’]	meter	None	For split warps, where the split happens.
farm_num	integer	dimensionless	0	Integer number of farm level refinements.
farm_type	string	-	square	Type of farm level refinements, options are full, box, cylinder, or stream.
farm_factor	number	dimensionless	1.0	Scaling factor for the size of the refinement.
turbine_num	integer	dimensionless	0	Integer number of turbine level refinements.
turbine_type	string	-	simple	Type of turbine refinement, options are sphere, simple, tear, or wake.
turbine_factor	number	dimensionless	1.0	Scaling factor for the size of the refinement.
refine_custom	[‘object’, ‘null’]	-	None	Allows for a dictionary of custom refine commands. See Custom Mesh Refinement
refine_power_calc	boolean	-	False	Bare minimum refinement around turbines to increase power calculation accuracy.

function_space

The finite element function space and the associated options that will be used to solve the problem.

Name	Type	Units	Default	Description
type	[‘string’, ‘null’]	-	None	Type of function space, options are linear or taylor_hood.
quadrature_degree	integer	dimensionless	6	Used when calculating integrals, larger values mean a more time-consuming but potentially more accurate calculation.
turbine_space	string	-	Quadrature	Used with numpy turbine_method, sets the space the turbines are calculate on.
turbine_degree	integer	dimensionless	6	Used with numpy turbine_method, sets degree.

boundary_conditions

These options set the boundaries and velocity/pressure options that will be enforced on the walls of the computational domain.

Name	Type	Units	Default	Description
vel_profile	[‘string’, ‘null’]	-	None	Inflow velocity profile, options are uniform, power, log, or turbsim.
HH_vel	number	meter/second	8.0	Velocity at hub height TODO: rename to ref_vel.
vel_height	[‘string’, ‘number’]	meter	HH	Sets the location of the reference velocity, i.e., the z-level at which HH_vel will be enforced.
power	number	dimensionless	0.25	Exponent for the power inflow.
k	number	dimensionless	0.4	The constant used in the log layer inflow.
turbsim_path	[‘string’, ‘null’]	-	None	Location for the turbsim inflow data.
inflow_angle	[‘number’, ‘array’]	radians	0.0	Angle of the inflow velocity.
boundary_names				Used for renaming the boundries. See Customizing Boundary Conditions
|--boundary_names:east	[‘string’, ‘null’]	-	None	Positive x.
|--boundary_names:north	[‘string’, ‘null’]	-	None	Positive y.
|--boundary_names:west	[‘string’, ‘null’]	-	None	Negative x.
|--boundary_names:south	[‘string’, ‘null’]	-	None	Negative y.
|--boundary_names:bottom	[‘string’, ‘null’]	-	None	Negative z.
|--boundary_names:top	[‘string’, ‘null’]	-	None	Positive z.
|--boundary_names:inflow	[‘string’, ‘null’]	-	None	Inflow, used in cylinder/circle.
|--boundary_names:outflow	[‘string’, ‘null’]	-	None	Outflow, used in cylinder/circle.
boundary_types				Used for changing the boundary types. See Customizing Boundary Conditions
|--boundary_types:inflow	[‘array’, ‘null’]	-	None	List of inflow bc names.
|--boundary_types:no_slip	[‘array’, ‘null’]	-	None	List of no_slip bc names.
|--boundary_types:free_slip	[‘array’, ‘null’]	-	None	List of free_slip bc names.
|--boundary_types:no_stress	[‘array’, ‘null’]	-	None	List of no_stress bc names.

problem

Options to define the problem that will be solved and add/modify different models that can be included, e.g., turbulence.

Name	Type	Units	Default	Description
type	[‘string’, ‘null’]	-	None	Type of model, options are stabilized, steady, taylor_hood, iterative_steady, or unsteady.
use_25d_model	boolean	-	False	Relax divergence free constraint to entrain momentum from ‘above’ and ‘below’.
viscosity	number	meter^2/second	0.1	Kinematic viscosity.
lmax	number	meter	15	Mixing length.
turbulence_model	[‘string’, ‘null’]	-	mixing_length	Turbulence model, options are mixing_length, smagorinsky, or None.
script_iterator	integer	dimensionless	0	Debugging tool, do not use.
use_corrective_force	boolean	-	False	Add a force to the weak form to allow the inflow to recover.
stability_eps	number	dimensionless	1.0	Stability term to help increase the well-posedness of the linear mixed formulation.
body_force	number	kg*meter/second^2	0.0	Set to a float to add a body force to the functional along the streamwise direction.

solver

These options control how the solver is executed and what properties are saved during the solution.

Name	Type	Units	Default	Description
type	string	-	steady	Type of solver, options are steady, iterative_steady, unsteady, multiangle, or imported_inflow.
pseudo_steady	boolean	-	False	Used with unsteady solver to create an iterative steady solver.
final_time	number	second	1.0	Final time of unsteady solve.
save_interval	number	second	1.0	How often to save during unsteady solve.
num_wind_angles	integer	dimensionless	1	Integer number of wind angles to sweep through for multiangle solve.
endpoint	boolean	-	False	Include the final wind angle in the sweep.
velocity_path	[‘string’, ‘null’]	-	None	Location of inflow velocities for multivelocity.
save_power	boolean	-	True	Save the power data to the data folder.
nonlinear_solver	string	-	snes	Type of nonlinear solver, options are snes or newton.
newton_relaxation	number	dimensionless	1.0	Relaxation parameter (0, 1] for Newton.
cfl_target	number	dimensionless	0.5	Target CFL number for unsteady solve.
cl_iterator	integer	dimensionless	0	Debugging tool, do not use.
save_all_timesteps	boolean	-	False	Save fields at every time step.

optimization

These options control how the optimization is carried out, how the objective function is calculated, and what constraints are applied.

Name	Type	Units	Default	Description
opt_type	string	-	maximize	Minimize or maximize.
control_types	[‘array’, ‘null’]	-	None	Controls to optimize, list of: layout, yaw, axial, chord, lift, or drag.
layout_bounds	array	meter	wind_farm	Special bound for layout optimizations.
objective_type	[‘object’, ‘string’]	-	power	Name of the function to maximize or minimize. See Defining Multiple Objective Functions
constraint_types				Set constraints based on objective_functions. Should be a dictionary of dictionaries with additional kws: target, scale, kwargs. Default inequality c(m)-target>=0 ==> c(m)>=target. See Defining Multiple/Custom Constraints
|--constraint_types:min_dist				Default constraint for layout opts. Restricts minimum distance between turbines.
|    |--constraint_types:min_dist:target	number	dimensionless	2	Sets the target for given constraint, in this case sets the minimum distance between turbines to be 2 RD.
|    |--constraint_types:min_dist:scale	number	dimensionless	1	Sets the scale for the constraint, use to match objective magnitude. Use -1 to flip constraint to target-c(m)>=0 ==> c(m) <= target.
|    |--constraint_types:min_dist:kwargs	[‘string’, ‘null’]	-	None	If constraint is based on an objective function with kwargs, set them here.
save_objective	boolean	-	False	Save the objective to a file in data/.
opt_turb_id	[‘string’, ‘array’, ‘integer’]	dimensionless	all	Which turbines to optimize, int or list or all.
record_time	number	second	0.0	When to start recording for unsteady objectives float or computed.
alm_DELs				Alm_DELs:.
|--alm_DELs:DEL_start_time	number	second	0	DEL_start_time: 0.
u_avg_time	number	second	0	When to start averaging velocity for use in objective functions.
opt_routine	string	-	SLSQP	Optimization method, options are SLSQP, L-BFGS-B, OM_SLSQP, or SNOPT (where SNOPT requires custom install).
obj_ref	number	same as objective	1.0	Sets the value of the objective function that will be treated as 1 by the SNOPT driver.
obj_ref0	number	same as objective	0.0	Sets the value of the objective function that will be treated as 0 by the SNOPT driver.
taylor_test	boolean	-	False	Run the Taylor test.
optimize	boolean	-	False	Optimize the problem.
gradient	boolean	-	False	Output the gradient.
verify_snopt	boolean	-	False	Use the SNOPT FD gradient verification.
check_totals	boolean	-	False	Check the total derivatives of the problem; optimize must be true as well.
hard_scaling_factor	number	dimensionless	1.0	A hard-coded scaling factor, objective_value = objective_value*hard_scaling_factor.
twist_range	number	radians	5.0	The envelope the twist control will be constrained to: baseline +/- twist_range.

postprocessing

A set of options to control methods executed after the WindSE simulation completes, including formatting outputs for compatibility with downstream coupled codes.

Name	Type	Units	Default	Description
write_floris_input	[‘array’, ‘null’]	-	None	Write specified output variables in a format that FLORIS can use as an input file.
write_floris_filename	string	-	floris_input.yaml	The filename to use when saving the FLORIS inputs.