Wind Turbine Model Parameters

All Parameterisations

ADM-R

Input files for the NREL 5 MW and 15 MW Reference Wind Turbines can be found at ​https://palm.muk.uni-hannover.de/trac/browser/palm/trunk/DATA

The influence of the nacelle on the flow is currently disabled due to segmentation faults on the FLOW HPC cluster (Oldenburg)

NAMELIST group name: wind_turbine_parameters

Parameter Name	FORTRAN Type	Default Value	Explanation
air_density	R	1.225	The air density (in kg/m3) is necessary to convert the aerodynamic torque of the rotor into a power (in W).
dt_data_output_wtm	R	0.0	Output interval (s) for NetCDF data. this parameter does not affect the deprecated ASCII data output that is written at each time step. With the default value 0.0 data will be output every time step.
gear_efficiency	R	1.0	Efficiency of the gear: Loss between rotor and generator.
gear_ratio	R	97.0	Gear ratio from rotor to generator.
generator_efficiency	R	0.944	Electric efficiency of the generator.
generator_inertia	R	534.116	Inertia of the generator (in kg m2).
generator_power_rated	R	5296610.0	Rated mechanical power of the wind turbine (in W). This parameter is specified once for all turbines, it is required for the pitch control.
generator_speed_rated	R	121.6805	Rated generator speed (in rad/s).
generator_torque_max	R	47402.91	Maximum Torque of the generator (in Nm). Should be set to a value of 10% above rated.
generator_torque_rate_max	R	15000.0	Maximum generator torque rate (in Nm/s). The maximum rate at which the generator torque can be increased to avoid overloading.
hub_x	R(100)	9999999.9	Longitudinal position of the rotor center (in m). This parameter needs to be specified for each turbine. Example: hub_x = 1000.0, 1500.0, 2000.0,
hub_y	R(100)	9999999.9	Lateral position of the rotor center (in m). This parameter needs to be specified for each turbine. Example: hub_y = 400.0, 400.0, 800.0,
hub_z	R(100)	9999999.9	Vertical position of the rotor center (in m). This parameter needs to be specified for each turbine. This represents the hub height of the turbine. Example: hub_z = 90.0, 90.0, 90.0,
n_airfoils	I	8	Number of airfoils of the used turbine model. The airfoil data should be provided in the additional input file run_name_wtm.
n_turbines	I	1	Number of the turbines to be included. Maximum is 100.
nacelle_cd	R(100)	0.85	Drag coefficient for each nacelle. This parameter needs to be specified for each turbine.
nacelle_radius	R(100)	1.5	Radius of the nacelle for each turbine (in m). This parameter has to be non-zero if the nacelle should be included. The parameter needs to be specified for each turbine.
pitch_angle	R(100)	0.0	Pitch angle for a constant pitch angle (in degrees). The value is used when pitch_control = .F.. This parameter needs to be specified for each turbine.
pitch_control	L	.F.	Parameter to switch on the pitch control. The pitch control controls the pitch angle to yield constant power for wind speeds greater than rated wind speed. The parameter generator_power_rated is used here.
pitch_rate	R	8.0	Maximum pitch rate (in degree/s).
region_15_min	R	70.16224	Lower generator speed boundary of region 1.5 (in rad/s). Region 1.5 is a transition region between region 1 and 2, region 1 is before cut-in wind speed, the wind is used to accelerate the rotor, no power is produced. Region 1.5 is a start-up region and represents the lower limit of the generator speed therefore limiting the operational speed range of the wind turbine. (Jonkman et al. 2009: Technical Report NREL/TP-500-38060, doi:10.2172/947422).
region_2_min	R	91.21091	Lower generator speed boundary of region 2 (in rad/s). (Jonkman et al. 2009: Technical Report NREL/TP-500-38060, doi:10.2172/947422).
region_2_slope	R	2.332287	Slope constant for region 2. In region 2 a constant tip speed ratio is maintained to optimize the power capture. In this region the generator torque is proportional to the square of the filtered generator speed. (Jonkman et al. 2009: Technical Report NREL/TP-500-38060, doi:10.2172/947422).
rotor_inertia	R	34784179.0	Inertia of the rotor (in kg m2).
rotor_radius	R(100)	63.0	Radius of the rotor (in m). This parameter needs to be specified for each turbine. Example: rotor_radius = 63.0, 63.0, 63.0,
rotor_speed	R(100)	0.9	Initial rotational speed for each turbine (in rad s-1). This parameter needs to be specified for each turbine.
segment_length_tangential	R	1.0	Length of each rotor segment the rotor area is divided into, in tangential direction, as factor of the minimum grid spacing (MIN(dx,dy,dz)). The default value is 1.0, in that case the tangential length of each segment is one grid spacing.
segment_width_radial	R	0.5	Length of each rotor segment the rotor area is divided into, in radial direction, as factor of the minimum grid spacing (MIN(dx,dy,dz)). The default value is 0.5, in that case the segments would have the width of half a grid spacing.
speed_control	L	.F.	Parameter to switch on the speed control. The speed control controls the rotational speed of the turbine for wind speeds less than rated wind speed.
smearing_kernel_size	R	2.0	Size of the smearing kernel given as multiples of the grid spacing dx. For details refer to ​https://palm.muk.uni-hannover.de/trac/wiki/doc/tec/wtm A large smearing kernel results in a too high tip speed ratio and power output. For coarse grid spacings (e.g. 12 grid points per rotor diameter) the power overestimation can be as large as 25 %. This error can be reduced by setting the smearing_kernel_size to 1. Do not use values below 1, because the number of grid cells inside the smearing kernel becomes very small (<10). In this case the sum of the body forces acting on the flow may be lower than the force acting on the rotor blade.
tilt_angle	R	0.0	Tilt angle of the rotor plane (in degrees). A positive angle means the bottom of the rotor plane is tilted away from the tower in order to avoid the blades hitting the tower. This parameter is specified once for all included turbines.
time_turbine_on	R	0.0	Simulation time at which the turbines are switched on.
tip_loss_correction	L	.F.	Parameter to switch on the tip loss correction.
tower_cd	R(100)	1.2	Drag coefficient for each tower. This parameter needs to be specified for each turbine.
tower_diameter	R(100)	4.0	Diameter of the tower of the wind turbine used below the rotor. This parameter has to be non-zero if a tower should be included. The parameter needs to be specified for every turbine separately.
yaw_angle	R(100)	0.0	Yaw angle for each turbine in degrees. A positive yaw means a rotation of the rotor in clockwise direction within the xy-plane. A yaw angle equal to 0 means facing west.
yaw_control	L	.F.	Parameter to switch on the yaw controller.
yaw_misalignment_max	R	0.08726	Maximum tolerated yaw misalignment (in rad).
yaw_misalignment_min	R	0.008726	Minimum yaw misalignment for which the actuator stops (in rad).
yaw_speed	R	0.005236	Speed of the yaw actuator (in rad/s).