def test_whfast_democraticheliocentric(self):
current_function_name = inspect.stack()[0][3][5:] # Remove first 5 characters "test_"
expected_json_filename, json_filename = common.setup(self.current_dirname, self.current_filename, current_function_name)
initial_time, time_step, time_limit, historic_snapshot_period, recovery_snapshot_period = common.simulation_properties()
consider_effects = posidonius.ConsiderEffects({
"tides": True,
"rotational_flattening": True,
"general_relativity": True,
"disk": True,
"wind": True,
"evolution": True,
})
general_relativity_implementation = "Kidder1995" # Assumes one central massive body
#general_relativity_implementation = "Anderson1975" # Assumes one central massive body
#general_relativity_implementation = "Newhall1983" # Considers all bodies
universe = posidonius.Universe(initial_time, time_limit, time_step, recovery_snapshot_period, historic_snapshot_period, consider_effects)
star_mass = 0.08 # Solar masses
star_dissipation_factor_scale = 1.0
star_position = posidonius.Axes(0., 0., 0.)
star_velocity = posidonius.Axes(0., 0., 0.)
#star_evolution = posidonius.Baraffe1998(star_mass) # M-Dwarf (mass = 0.10) or SolarLike ConstantDissipation (mass = 1.0)
#star_evolution = posidonius.Baraffe2015(star_mass) # mass = 0.01 .. 1.40
star_evolution = posidonius.Leconte2011(star_mass) # BrownDwarf (mass = 0.01 .. 0.08)
#star_evolution = posidonius.BolmontMathis2016(star_mass) # SolarLike Evolving dissipation (mass = 0.40 .. 1.40)
#star_evolution = posidonius.GalletBolmont2017(star_mass) # SolarLike Evolving dissipation (mass = 0.30 .. 1.40)
#star_evolution = posidonius.LeconteChabrier2013(False) # Jupiter without dissipation of dynamical tides
#star_evolution = posidonius.LeconteChabrier2013(True) # Jupiter with dissipation of dynamical tides
#star_evolution = posidonius.NonEvolving()
star = common.brown_dwarf(star_mass, star_dissipation_factor_scale, star_position, star_velocity, general_relativity_implementation, star_evolution)
universe.add_particle(star)
common.basic_configuration(universe)
############################################################################
#whfast_alternative_coordinates="Jacobi"
whfast_alternative_coordinates="DemocraticHeliocentric"
#whfast_alternative_coordinates="WHDS"
#universe.write(json_filename, integrator="LeapFrog")
#universe.write(json_filename, integrator="IAS15")
universe.write(json_filename, integrator="WHFast", whfast_alternative_coordinates=whfast_alternative_coordinates)
if not os.path.exists(expected_json_filename):
shutil.copyfile(json_filename, expected_json_filename)
self.assertTrue(filecmp.cmp(json_filename, expected_json_filename, shallow=False), "Generated JSON case is not equal to the expected one: {} {}".format(json_filename, expected_json_filename))
shutil.rmtree(os.path.dirname(json_filename))
def calculate_spin(angular_frequency, inclination, obliquity, position,
velocity):
"""
Old version of calculate spin used in all cases in Bolmont et al 2015 except
for cases 6, 6', 6'', 6''' and 7
"""
if inclination == 0.:
# No inclination, spin can already be calculated:
x = angular_frequency * np.sin(
obliquity) # zero if there is no obliquity
y = 0.
z = angular_frequency * np.cos(obliquity)
else:
# Calculation of orbital angular momentum (without mass and in AU^2/day)
horb_x = position.y() * velocity.z() - position.z() * velocity.y()
horb_y = position.z() * velocity.x() - position.x() * velocity.z()
horb_z = position.x() * velocity.y() - position.y() * velocity.x()
horbn = np.sqrt(
np.power(horb_x, 2) + np.power(horb_y, 2) + np.power(horb_z, 2))
# Spin taking into consideration the inclination:
x = angular_frequency * (
horb_x /
(horbn * np.sin(inclination))) * np.sin(obliquity + inclination)
y = angular_frequency * (
horb_y /
(horbn * np.sin(inclination))) * np.sin(obliquity + inclination)
z = angular_frequency * np.cos(obliquity + inclination)
return posidonius.Axes(x, y, z)
def _posvel(star_mass, planet_mass, a):
zeros = posidonius.Axes(0., 0., 0.)
#////////// Specify initial position and velocity for a stable orbit
#////// Keplerian orbital elements, in the `asteroidal' format of Mercury code
#a = 0.018; # semi-major axis (in AU)
e = 0.1
# eccentricity
i = 5. * posidonius.constants.DEG2RAD
# inclination (degrees)
p = 0. * posidonius.constants.DEG2RAD
# argument of pericentre (degrees)
n = 0. * posidonius.constants.DEG2RAD
# longitude of the ascending node (degrees)
l = 0. * posidonius.constants.DEG2RAD
# mean anomaly (degrees)
p = (p + n)
# Convert to longitude of perihelion !!
q = a * (1.0 - e)
# perihelion distance
position, velocity = posidonius.calculate_cartesian_coordinates(
planet_mass,
q,
e,
i,
p,
n,
l,
masses=[star_mass],
positions=[zeros],
velocities=[zeros])
return position, velocity
def _spin(obliquity, rotation_period, star_mass, planet_mass, planet_position,
planet_velocity):
zeros = posidonius.Axes(0., 0., 0.)
#////// Initialization of planetary spin
angular_frequency = posidonius.constants.TWO_PI / (rotation_period / 24.
) # days^-1
keplerian_orbital_elements = posidonius.calculate_keplerian_orbital_elements(
planet_mass,
planet_position,
planet_velocity,
masses=[star_mass],
positions=[zeros],
velocities=[zeros])
inclination = keplerian_orbital_elements[3]
spin = posidonius.calculate_spin(angular_frequency, inclination, obliquity)
return spin
recovery_snapshot_period,
historic_snapshot_period, consider_effects)
star_mass = 0.08 # Solar masses
star_radius_factor = 0.845649342247916
# [start correction] -------------------------------------------------------
# To reproduce Bolmont et al. 2015:
# Mercury-T was using R_SUN of 4.67920694e-3 AU which is not the IAU accepted value
# thus, to reproduce Mercury-T results the star radius factor should be slighly modified:
star_radius_factor = star_radius_factor * (4.67920694e-3 /
posidonius.constants.R_SUN)
# [end correction] ---------------------------------------------------------
star_radius = star_radius_factor * posidonius.constants.R_SUN
star_radius_of_gyration = 4.41e-01 # Brown dwarf
star_position = posidonius.Axes(0., 0., 0.)
star_velocity = posidonius.Axes(0., 0., 0.)
# Initialization of stellar spin
star_rotation_period = 70.0 # hours
star_angular_frequency = posidonius.constants.TWO_PI / (
star_rotation_period / 24.) # days^-1
star_spin = posidonius.Axes(0., 0., star_angular_frequency)
star_tides_parameters = {
"dissipation_factor_scale": 0.01,
"dissipation_factor": 2.006 * 3.845764e4,
"love_number": 0.307,
}
star_tides_model = posidonius.effects.tides.ConstantTimeLag(
star_tides_parameters)