<!– SPDX-FileCopyrightText: 2025 Uwe Fechner
SPDX-License-Identifier: MIT –>
Configuration
To configure the parameters of the kite models, edit the file data/settings.yaml, or create a copy under a different name and change the name of the active configuration in the file data/system.yaml.
Parameters
The following parameters are used by this package:
system:
log_file: "data/ram_air_kite" # filename without extension [replay only]
# use / as path delimiter, even on Windows
time_lapse: 1.0 # relative replay speed
sim_time: 100.0 # simulation time [sim only]
segments: 3 # number of tether segments
sample_freq: 20 # sample frequency in Hz
zoom: 0.03 # zoom factor for the system view
kite_scale: 3.0 # relative zoom factor for the 4 point kite
fixed_font: "" # name or filepath+filename of alternative fixed pitch font
initial:
l_tethers: [50.0, 50.0, 50.0] # initial tether length [m]
elevation: 70.8 # initial elevation angle [deg]
v_reel_outs: [0.0, 0.0, 0.0] # initial reel out speed [m/s]
solver:
solver: "FBDF"
abs_tol: 0.01 # absolute tolerance of the DAE solver [m, m/s]
rel_tol: 0.01 # relative tolerance of the DAE solver [-]
relaxation: 0.6 # relaxation factor of inner linear Newton solver, needed for quasi-steady solver
kite:
model: "data/ram_air_kite_body.obj" # 3D model of the kite
foil_file: "data/ram_air_kite_foil.dat" # filename for the foil shape
physical_model: "ram" # name of the kite model to use (KPS3, KPS4 or SymbolicAWEModel)
top_bridle_points: # top bridle points that are not on the kite body in CAD frame
- [0.290199, 0.784697, -2.61305]
- [0.392683, 0.785271, -2.61201]
- [0.498202, 0.786175, -2.62148]
- [0.535543, 0.786175, -2.62148]
crease_frac: 0.82 # distance along normalized foil chord for the trailing edge deformation crease
bridle_fracs: [0.088, 0.31, 0.58, 0.93] # distances along normalized foil chord for bridle attachment points
mass: 0.9 # kite mass [kg]
quasi_static: false # whether to use quasi static kite points or not
tether:
bridle_tether_diameter: 2 # [mm]
power_tether_diameter: 2 # [mm]
steering_tether_diameter: 1 # [mm]
cd_tether: 0.958 # drag coefficient of the tether
damping: 473.0 # unit damping coefficient [Ns]
c_spring: 614600.0 # unit spring constant coefficient [N]
rho_tether: 724.0 # density of Dyneema [kg/m³]
e_tether: 55000000000.0 # axial tensile modulus of Dyneema (M.B. Ruppert) [Pa]
# SK75: 109 to 132 GPa according to datasheet
winch:
winch_model: "TorqueControlledMachine" # or AsynchMachine
max_force: 4000 # maximal (nominal) tether force; short overload allowed [N]
v_ro_max: 8.0 # maximal reel-out speed [m/s]
v_ro_min: -8.0 # minimal reel-out speed (=max reel-in speed) [m/s]
drum_radius: 0.110 # radius of the drum [m]
max_acc: 4.0 # maximal acceleration of the winch [m/s²]
gear_ratio: 1.0 # gear ratio of the winch [-]
inertia_total: 0.024 # total inertia, as seen from the motor/generator [kgm²]
f_coulomb: 122.0 # coulomb friction [N]
c_vf: 30.6 # coefficient for the viscous friction [Ns/m]
p_speed: 1.0 # proportional gain of the winch speed controller [-]
i_speed: 0.1 # integral gain of the winch speed controller [-]
environment:
v_wind: 15.51 # wind speed at reference height [m/s]
upwind_dir: -90.0 # upwind direction [deg]
temp_ref: 15.0 # temperature at reference height [°C]
height_gnd: 0.0 # height of groundstation above see level [m]
h_ref: 6.0 # reference height for the wind speed [m]
rho_0: 1.225 # air density at zero height and 15 °C [kg/m³]
alpha: 0.08163 # exponent of the wind profile law
z0: 0.0002 # surface roughness [m]
profile_law: 3 # 1=EXP, 2=LOG, 3=EXPLOG, 4=FAST_EXP, 5=FAST_LOG, 6=FAST_EXPLOG
# the following parameters are for calculating the turbulent wind field using the Mann model
use_turbulence: 0.0 # turbulence intensity relative to Cabau, NL
v_wind_gnds: [3.483, 5.324, 8.163] # wind speeds at ref height for calculating the turbulent wind field [m/s]
avg_height: 200.0 # average height during reel out [m]
rel_turbs: [0.342, 0.465, 0.583] # relative turbulence at the v_wind_gnds
i_ref: 0.14 # is the expected value of the turbulence intensity at 15 m/s.
v_ref: 42.9 # five times the average wind speed in m/s at hub height over the full year [m/s]
# Cabau: 8.5863 m/s * 5.0 = 42.9 m/s
height_step: 2.0 # use a grid with 2m resolution in z direction [m]
grid_step: 2.0 # grid resolution in x and y direction [m]