def setUp(self):
config = {
'drag coefficient': 0.7,
'members': [{
'end1': [0, 0, 0],
'end2': [0, 0, -10],
'diameter': [[0, 3, 5, 10], [2.2, 2.2, 5, 5]],
'strip width': 0.5,
}],
}
self.model = ViscousDragModel(config)
def setUp(self):
config = {
'drag coefficient': 0.7,
'inertia coefficient': 2.0,
'members': [{
'end1': [0, 0, 0],
'end2': [0, 0, -10],
'diameter': 2.3,
'strip width': 1,
}],
}
self.model = ViscousDragModel(config)
def Morison_added_mass(w, draft, radius, Cm=2.0):
"""Calculate added mass and damping from Morison strip model of
uniform cylinder"""
from whales.viscous_drag import ViscousDragModel
Morison_model = ViscousDragModel({
'inertia coefficient':
Cm,
'members': [{
'end1': [0, 0, 0],
'end2': [0, 0, -draft],
'diameter': 2 * radius,
'strip width': 1.0,
}]
})
A1 = Morison_model.Morison_added_mass()
A = np.tile(A1, (len(w), 1, 1))
return LinearSystem(A, zeros_like(A), zeros_like(A))
def excitation_force(w, z1, z2, diameter, Cm=2):
"""Calculate the excitation force. Specific for now to vertical
cylinders of varying diameter.
``z1``, ``z2``: coordinates of ends of element
``diameter``: array (2 x Npoints) diameter at each z value
"""
config = {
'end1': [0, 0, z1],
'end2': [0, 0, z2],
'diameter': diameter,
'strip width': 1.0,
}
Morison_model = ViscousDragModel({
'inertia coefficient': Cm,
'members': [config],
})
X = Morison_model.Morison_inertial_force(w)
return X
def added_mass(w, z1, z2, diameter, Cm=2):
"""Calculate the added mass/damping. Specific for now to vertical
cylinders of varying diameter.
``z1``, ``z2``: coordinates of ends of element
``diameter``: array (2 x Npoints) diameter at each z value
"""
config = {
'end1': [0, 0, z1],
'end2': [0, 0, z2],
'diameter': diameter,
'strip width': 1.0,
}
Morison_model = ViscousDragModel({
'inertia coefficient': Cm,
'members': [config],
})
A1 = Morison_model.Morison_added_mass()
A = np.tile(A1, (len(w), 1, 1))
return LinearSystem(A, zeros_like(A), zeros_like(A))
def __init__(self, config, frequency_values):
self.config = config
self.w = frequency_values
# Build structural model
self.structure = FloatingTurbineStructure(config['structure'])
# Get hydrodynamic/static information
h = config['hydrodynamics']
rho = config['constants']['water density']
first_order = WAMITData(h['WAMIT path'], water_density=rho)
if 'QTF path' in h:
second_order = SecondOrderData(h['QTF path'], water_density=rho)
else:
second_order = None
self.hydro_info = HydrodynamicsInfo(first_order, second_order)
# Get mooring line behaviour
l = config['mooring']['linear']
self.mooring_static = np.asarray(l['static force'])
self.mooring_stiffness = np.asarray(l['stiffness'])
# Extra damping
self.B_extra = np.asarray(h.get('extra damping', np.zeros(6)))
if self.B_extra.ndim == 1:
self.B_extra = np.diag(self.B_extra)
# Viscous drag model
if 'Morison elements' in h:
self.morison = ViscousDragModel(h['Morison elements'])
else:
self.morison = None
self.Bv = np.zeros((6, 6))
self.Fvc = np.zeros(6)
self.Fvv = np.zeros((len(self.w), 6))
# Wave-drift damping
self.Bwd = np.zeros((6, 6))
def setUp(self):
config = {
'drag coefficient': 0.7,
'members': [{
# # Member in x-direction
# 'end1': [0, 0, 0],
# 'end2': [1, 0, 0],
# 'diameter': 1,
# 'strip width': 1,
# }, {
# Member in z-direction
'end1': [0, 0, 0],
'end2': [0, 0, 1],
'diameter': 1,
'strip width': 1,
# }, {
# # Member in xy plane at 30deg from x axis
# 'end1': [0, 0, 0],
# 'end2': [np.cos(30*np.pi/180), np.sin(30*np.pi/180), 0],
# 'diameter': 1,
# 'strip width': 1,
}],
}
self.model = ViscousDragModel(config)
