def update(self, velocity_from_body, mu, v_inf, omega, verbose):
"""Updates the shape of the wake based on solved flow results.
Parameters
----------
velocity_from_body : callable
Function which will return the velocity induced by the body at a given set of points.
mu : ndarray
Vector of doublet strengths.
v_inf : ndarray
Freestream velocity vector.
omega : ndarray
Angular rate vector.
verbose : bool
"""
# Update number of segments
self.N_segments += 1
if verbose:
print()
prog = OneLineProgress(
self.N_segments + 1,
msg=" Updating wake shape with {0} segments".format(
self.N_segments))
# Initialize storage
new_locs = np.zeros((self.N, self.N_segments, 3))
# Get starting locations (offset slightly from origin to avoid singularities)
curr_loc = self._vertices[:, 0, :] + self._filament_dirs * 0.01
if verbose: prog.display()
# Loop through filament segments (the first vertex never changes)
next_loc = np.zeros((self.N, 3))
for i in range(1, self.N_segments + 1):
# Determine velocities at current point
v0 = velocity_from_body(curr_loc) + v_inf[
np.newaxis, :] - vec_cross(omega, curr_loc)
v0 += self._get_velocity_from_other_filaments_and_edges(
curr_loc, mu)
# Guess of next location
next_loc = curr_loc + self.l * v0 / vec_norm(v0)[:, np.newaxis]
# Iteratively correct
for j in range(self._corrector_iterations):
# Velocities at next location
v1 = velocity_from_body(next_loc) + v_inf[np.newaxis, :]
v1 += self._get_velocity_from_other_filaments_and_edges(
next_loc, mu)
# Correct location
v_avg = 0.5 * (v0 + v1)
next_loc = curr_loc + self.l * v_avg / vec_norm(
v_avg)[:, np.newaxis]
# Store
new_locs[:, i - 1, :] = np.copy(next_loc)
# Move downstream
curr_loc = np.copy(next_loc)
if verbose: prog.display()
# Store the new locations
self._vertices[:, 1:self.N_segments + 1, :] = new_locs