"""
Simulate the hydrodynamial evolve a disk with a single bump around a star
"""
from amuse.lab import *
from amuse.io import store
def main(Mstar = 1|units.MSun,
Ndisk=100, Mdisk=0.9|units.MSun,
Rmin=1.0|units.AU, Rmax=100.0|units.AU,
Mbump=0.1|units.MSun,Rbump=10.0|units.AU, abump=10|units.AU,
t_end=1, n_steps=10):
converter=nbody_system.nbody_to_si(Mdisk, Rmin)
from amuse.ext.protodisk import ProtoPlanetaryDisk
bodies = ProtoPlanetaryDisk(Ndisk, convert_nbody=converter,
densitypower=1.5, Rmin=1.0,
Rmax=Rmax/Rmin, q_out=1.0,
discfraction=1.0).result
Mdisk = bodies.mass.sum()
bodies.move_to_center()
com = bodies.center_of_mass()
mm = Mdisk/float(Ndisk)
Nbump = Mbump/mm
bump = new_plummer_gas_model(Nbump, convert_nbody=nbody_system.nbody_to_si(Mbump, Rbump))
bump.x += abump
r_bump = abump
inner_particles = bodies.select(lambda r: (com-r).length()<abump,["position"])
M_inner = inner_particles.mass.sum() + Mstar
v_circ = (constants.G*M_inner*(2./r_bump - 1./abump)).sqrt().value_in(units.kms)
bump.velocity += [0, v_circ, 0] | units.kms
bodies.add_particles(bump)
star=Particles(1)
star.mass=Mstar
star.radius= Rmin
star.position = [0, 0, 0] | units.AU
star.velocity = [0, 0, 0] | units.kms
import math
P_bump = (abump**3*4*math.pi**2/(constants.G*(Mbump+Mstar))).sqrt()
t_end *= P_bump
hydro = Gadget2(converter)
hydro.gas_particles.add_particles(bodies)
hydro.dm_particles.add_particles(star)
Etot_init = hydro.kinetic_energy + hydro.potential_energy + hydro.thermal_energy
particles = ParticlesSuperset([star, bodies])
particles.move_to_center()
particles.new_channel_to(hydro.particles).copy()
bodies.h_smooth = Rmin # for the plotting routine
channel_to_star = hydro.dm_particles.new_channel_to(star)
channel_to_bodies = hydro.gas_particles.new_channel_to(bodies)
write_set_to_file(star, "stars.hdf5","hdf5")
write_set_to_file(bodies, "hydro.hdf5","hdf5")
time = 0.0 | t_end.unit
dt = t_end/float(n_steps)
while time < t_end:
time += dt
hydro.evolve_model(time)
channel_to_star.copy()
channel_to_bodies.copy()
write_set_to_file(star, "stars.hdf5","hdf5")
write_set_to_file(bodies, "hydro.hdf5","hdf5")
star.radius = Rmin
from hydro_sink_particles import hydro_sink_particles
lost = hydro_sink_particles(star, bodies)
if len(lost)>0:
hydro.particles.remove_particles(lost)
hydro.particles.synchronize_to(particles)
print "Disk=", hydro.model_time, len(bodies), len(lost), lost.mass.sum(), star.mass
Ekin = hydro.kinetic_energy
Epot = hydro.potential_energy
Eth = hydro.thermal_energy
Etot = Ekin + Epot + Eth
print "T=", hydro.get_time(), "M=", hydro.gas_particles.mass.sum(),
print "E= ", Etot, "Q= ", (Ekin+Eth)/Epot, "dE=", (Etot_init-Etot)/Etot
print "Star=", hydro.model_time, star[0].mass, star[0].position
hydro.stop()
def new_option_parser():
from amuse.units.optparse import OptionParser
result = OptionParser()
result.add_option("-N", dest="Ndisk", type="int",default = 100,
help="number of stars [10]")
result.add_option("-n", dest="n_steps", type="int",default = 10,
help="number of steps [10]")
result.add_option("-t",
dest="t_end", type="float", default = 1,
help="end time of the simulation in bump orbits")
result.add_option("-M", dest="Mstar", type="float", default = 1|units.MSun,
help="Mass of the central star [%default]")
result.add_option("--Mdisk", dest="Mdisk", type="float",
default = 0.9|units.MSun,
help="Mass of the disk [%default]")
result.add_option("-r", unit=units.AU,
dest="Rmin", type="float", default = 10 |units.AU,
help="inner disk radius [%default]")
result.add_option("-R", unit=units.AU,
dest="Rmax", type="float", default = 100 | units.AU,
help="outer disk radius [%default]")
result.add_option("--Mbump", unit=units.MSun,
dest="Mbump", type="float", default = 0.1 | units.MSun,
help="bump mass [%default]")
result.add_option("--Rbump", unit=units.AU,
dest="Rbump", type="float", default = 10 | units.AU,
help="bump radius [%default]")
result.add_option("-a", unit=units.AU,
dest="abump", type="float", default = 20 | units.AU,
help="distance of bump from star [%default]")
return result
if __name__ in ('__main__', '__plot__'):
o, arguments = new_option_parser().parse_args()
main(**o.__dict__)
Keywords: python, amuse, astrophysics, matplotlib, pylab, example, codex (see how-to-search-examples)