from __future__ import print_function
import sys
import mesh.patch as patch
import numpy as np
from util import msg
import math
[docs]def init_data(my_data, rp):
""" initialize the sedov problem """
msg.bold("initializing the sedov problem...")
# make sure that we are passed a valid patch object
if not isinstance(my_data, patch.CellCenterData2d):
print("ERROR: patch invalid in sedov.py")
print(my_data.__class__)
sys.exit()
# get the density, momenta, and energy as separate variables
dens = my_data.get_var("density")
xmom = my_data.get_var("x-momentum")
ymom = my_data.get_var("y-momentum")
ener = my_data.get_var("energy")
# initialize the components, remember, that ener here is rho*eint
# + 0.5*rho*v**2, where eint is the specific internal energy
# (erg/g)
dens[:, :] = 1.0
xmom[:, :] = 0.0
ymom[:, :] = 0.0
E_sedov = 1.0
r_init = rp.get_param("sedov.r_init")
gamma = rp.get_param("eos.gamma")
pi = math.pi
xmin = rp.get_param("mesh.xmin")
xmax = rp.get_param("mesh.xmax")
ymin = rp.get_param("mesh.ymin")
ymax = rp.get_param("mesh.ymax")
xctr = 0.5*(xmin + xmax)
yctr = 0.5*(ymin + ymax)
# initialize the pressure by putting the explosion energy into a
# volume of constant pressure. Then compute the energy in a zone
# from this.
nsub = rp.get_param("sedov.nsub")
dist = np.sqrt((my_data.grid.x2d - xctr)**2 +
(my_data.grid.y2d - yctr)**2)
p = 1.e-5
ener[:, :] = p/(gamma - 1.0)
for i, j in np.transpose(np.nonzero(dist < 2.0*r_init)):
xsub = my_data.grid.xl[i] + (my_data.grid.dx/nsub)*(np.arange(nsub) + 0.5)
ysub = my_data.grid.yl[j] + (my_data.grid.dy/nsub)*(np.arange(nsub) + 0.5)
xx, yy = np.meshgrid(xsub, ysub, indexing="ij")
dist = np.sqrt((xx - xctr)**2 + (yy - yctr)**2)
n_in_pert = np.count_nonzero(dist <= r_init)
p = n_in_pert*(gamma - 1.0)*E_sedov/(pi*r_init*r_init) + \
(nsub*nsub - n_in_pert)*1.e-5
p = p/(nsub*nsub)
ener[i, j] = p/(gamma - 1.0)
[docs]def finalize():
""" print out any information to the user at the end of the run """
msg = """
The script analysis/sedov_compare.py can be used to analyze these
results. That will perform an average at constant radius and
compare the radial profiles to the exact solution. Sample exact
data is provided as analysis/cylindrical-sedov.out
"""
print(msg)