def make_parameters_simulation(gamma, key_viscosity):
""" Make parameters of the first simulation. """
# Parameters simulation
F = np.sin(pi / 4)
sigma = 1
# Create parameters
params = Simul.create_default_params()
# Operator parameters
params.oper.nx = nx
params.oper.ny = nz = nx // 4
params.oper.Lx = Lx = 2 * pi
params.oper.Ly = Lz = Lx * (nz / nx)
params.oper.NO_SHEAR_MODES = True
params.oper.coef_dealiasing = 0.6666
# Forcing parameters
params.forcing.enable = True
params.forcing.type = "tcrandom_anisotropic"
params.forcing.key_forced = "ap_fft"
params.forcing.nkmax_forcing = nkmax_forcing = 8
params.forcing.nkmin_forcing = nkmin_forcing = 4
params.forcing.normalized.constant_rate_of = "energy"
params.forcing.tcrandom_anisotropic.angle = np.arcsin(F)
# Compute other parameters (Normalization by the energy..)
tau_af = 1 # Forcing time equal to 1
k_f = ((nkmax_forcing + nkmin_forcing) / 2) * max(2 * pi / Lx, 2 * pi / Lz)
forcing_rate = (1 / tau_af**3) * ((2 * pi) / k_f)**2
omega_af = 2 * pi / tau_af
params.N = (gamma / F) * omega_af
# Choose vis, key_viscosity=key_viscositycosity
if key_viscosity == "nu_2":
params.nu_2 = nu_2
elif key_viscosity == "nu_8":
params.nu_8 = nu_8
else:
raise ValueError(f"{key_viscosity} not known.")
# Continuation on forcing...
params.forcing.forcing_rate = forcing_rate
params.forcing.tcrandom.time_correlation = sigma * (
pi / (params.N * F)) # time_correlation = wave period
# Time stepping parameters
params.time_stepping.USE_CFL = True
params.time_stepping.t_end = t_end
# Initialization parameters
params.init_fields.type = "noise"
modify_parameters(params)
return params
def _create_object_params():
params = Simul.create_default_params()
try:
params.N = 1.0
except AttributeError:
pass
# Operator parameters
params.oper.nx = params.oper.ny = 32
params.oper.Lx = params.oper.Ly = 2 * pi
# Forcing parameters
params.forcing.enable = False
params.forcing.type = 'tcrandom_anisotropic'
try:
params.forcing.tcrandom_anisotropic.angle = '45.0°'
except AttributeError:
pass
params.forcing.nkmin_forcing = 8
params.forcing.nkmax_forcing = 12
# Compute \omega_l
from math import radians
if "°" in params.forcing.tcrandom_anisotropic.angle:
angle = params.forcing.tcrandom_anisotropic.angle.split("°")
angle = float(angle[0])
else:
raise ValueError("Angle should be contain the degrees symbol °.")
omega_l = params.N * np.sin(radians(angle))
params.forcing.tcrandom.time_correlation = 2 * pi / omega_l
params.forcing.key_forced = 'ap_fft'
# Time stepping parameters
params.time_stepping.USE_CFL = True
params.time_stepping.USE_T_END = True
params.time_stepping.t_end = 2.
# Output parameters
params.output.HAS_TO_SAVE = False
params.output.sub_directory = 'tests'
return params
"""Script for a short simulation with the solver ns2d.strat """ import numpy as np from math import pi from fluiddyn.util import mpi from fluidsim.solvers.ns2d.strat.solver import Simul params = Simul.create_default_params() gamma = 1.0 nb_wavelength = 2 nz = nb_wavelength * 30 * 2 nx = 6 * nz params.time_stepping.t_end = 100.0 params.short_name_type_run = "quasi1d" aspect_ratio = nz / nx theta = np.arctan(aspect_ratio / nb_wavelength) F = np.sin(theta) kf = 2 * pi omega_af = 2 * pi forcing_rate = omega_af**3 / kf**2 Lx = 2 * pi / kf * np.sqrt(1 + (nb_wavelength / aspect_ratio)**2) Lz = aspect_ratio * Lx
def make_parameters_simulation(gamma,
F,
sigma,
nu_8,
t_end=10,
NO_SHEAR_MODES=False):
## Operator parameters
anisotropy_domain = 4 # anisotropy_domain = nx / nz
nx = 240
nz = nx // anisotropy_domain
Lx = 2 * pi
Lz = Lx * (nz / nx) # deltax = deltay
coef_dealiasing = 0.6666
# Time stepping parameters
USE_CFL = True
deltat0 = 0.0005
# t_end = 5.
## Forcing parameters
forcing_enable = True
nkmax_forcing = 8
nkmin_forcing = 4
tau_af = 1 # Forcing time equal to 1
######################
#######################
# Create parameters
params = Simul.create_default_params()
# Operator parameters
params.oper.nx = nx
params.oper.ny = nz
params.oper.Lx = Lx
params.oper.Ly = Lz
params.oper.NO_SHEAR_MODES = NO_SHEAR_MODES
params.oper.coef_dealiasing = coef_dealiasing
# Forcing parameters
params.forcing.enable = forcing_enable
params.forcing.type = 'tcrandom_anisotropic'
params.forcing.key_forced = "ap_fft"
params.forcing.nkmax_forcing = nkmax_forcing
params.forcing.nkmin_forcing = nkmin_forcing
params.forcing.tcrandom_anisotropic.angle = np.arcsin(F)
# Compute other parameters
k_f = ((nkmax_forcing + nkmin_forcing) / 2) * max(2 * pi / Lx, 2 * pi / Lz)
forcing_rate = (1 / tau_af**7) * ((2 * pi) / k_f)**2
omega_af = 2 * pi / tau_af
params.N = (gamma / F) * omega_af
params.nu_8 = nu_8
# Continuation on forcing...
params.forcing.forcing_rate = forcing_rate
params.forcing.tcrandom.time_correlation = sigma * (
pi / (params.N * F)) # time_correlation = wave period
# Time stepping parameters
params.time_stepping.USE_CFL = USE_CFL
params.time_stepping.deltat0 = deltat0
params.time_stepping.t_end = t_end
# Initialization parameters
params.init_fields.type = "noise"
modify_parameters(params)
return params