def write_field(self,
x_seq,
y_seq,
z_seq,
vel=True,
pot=True,
perturbation=False):
dim = [x_seq[-1], y_seq[-1], z_seq[-1]]
x_grid = numpy.linspace(*x_seq)
y_grid = numpy.linspace(*y_seq)
z_grid = numpy.linspace(*z_seq)
vertices = [
paraBEM.PanelVector3(x, y, z) for z in z_grid for y in y_grid
for x in x_grid
]
for vert in vertices:
if pot:
self.case.off_body_potential(vert)
if vel or perturbation:
self.case.off_body_velocity(vert)
with open(self._dir + "/field.vtk", "w") as _file:
writer = VtkWriter()
writer.structed_grid(_file, "field_data", dim)
writer.points(_file, vertices)
if pot:
_potential = [vert.potential for vert in vertices]
writer.data(_file,
_potential,
"potential",
data_type="POINT_DATA")
if vel:
_velocity = [vert.velocity for vert in vertices]
writer.data(_file,
_velocity,
"velocity",
_type="VECTORS",
data_type="POINT_DATA")
if perturbation:
_velocity = [
vert.velocity.x - self.case.v_inf.x for vert in vertices
]
writer.data(_file,
_velocity,
"velocity",
data_type="POINT_DATA")
def from_OBJ(cls, path):
def load_obj_file(path):
trailing_edges = []
panels = []
vertices = []
with open(path, "r") as inp:
text_list = inp.readlines()
for line in text_list:
chars = line.split()
if chars[0] == "v":
vertices.append([float(number) for number in chars[1:]])
elif chars[0] == "f":
panels.append([int(number) - 1 for number in chars[1:]])
elif chars[0] == "l":
trailing_edges.append(
[int(number) - 1 for number in chars[1:]])
return vertices, panels, trailing_edges
def sort_and_order(panels, vertices):
# deleting all vertices not used by the mesh
# overwrites the panels and return the new vertices list
orderd_vert_nr = list(set([vert for pol in panels
for vert in pol]))
vertices_set = [vertices[i] for i in orderd_vert_nr]
mesh_dict = dict(zip(orderd_vert_nr, range(len(orderd_vert_nr))))
panels = [[mesh_dict[vert] for vert in pol] for pol in panels]
return panels, vertices_set
def sort_wake(trailing_edges):
# makes a orderd list of the trailing_edge
w_temp = trailing_edges[0]
trailing_edges.pop(0)
i = 0
j = 0 # stop if there is an error in the data
while len(trailing_edges) and j < 10000:
if trailing_edges[i][0] == w_temp[0]:
w_temp = [trailing_edges[i][1]] + w_temp
trailing_edges.pop(i)
elif trailing_edges[i][1] == w_temp[0]:
w_temp = [trailing_edges[i][0]] + w_temp
trailing_edges.pop(i)
elif trailing_edges[i][0] == w_temp[-1]:
w_temp = w_temp + [trailing_edges[i][1]]
trailing_edges.pop(i)
elif trailing_edges[i][1] == w_temp[-1]:
w_temp = w_temp + [trailing_edges[i][0]]
trailing_edges.pop(i)
i = int((i + 1) * (i < (len(trailing_edges) - 1)))
j += 1
# abbort if j == 10000: this means that the trailing_edge is not a single line
# this has to be exdented to wakes consisting of more than one wake edge !!!
return w_temp
def wake_from_mesh(trailing_edges, vertices, vertices_set):
# replacing vertices with mesh vertices
norm = lambda x, y: ((x[0] - y[0])**2 + (x[1] - y[1])**2 +
(x[2] - y[2])**2)**(0.5)
vert_dict = dict(zip(range(len(vertices)), vertices))
max_size = 0.0001
wake_dict = {}
for i in trailing_edges:
v1 = vert_dict[i]
for j, v2 in enumerate(vertices_set):
if norm(v1, v2) < max_size:
wake_dict[i] = j
return wake_dict
mesh = cls()
vertices, panels, trailing_edges = load_obj_file(path)
panels, vertices_set = sort_and_order(panels, vertices)
mesh.vertices = [
paraBEM.PanelVector3(*vertex) for vertex in vertices_set
]
mesh.panels = [
paraBEM.Panel3([mesh.vertices[nr] for nr in pol]) for pol in panels
]
if len(trailing_edges) > 0:
trailing_edges = sort_wake(trailing_edges)
wake_dict = wake_from_mesh(trailing_edges, vertices, vertices_set)
mesh.trailing_edges = [
mesh.vertices[wake_dict[i]] for i in trailing_edges
]
return mesh
# -*- coding: utf-8 -*-
from __future__ import division
import os
import numpy as np
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import paraBEM
from paraBEM.pan3d import doublet_3_0_n0, doublet_3_0_sphere, doublet_3_0_vsaero
from paraBEM.utils import check_path
pnt1 = paraBEM.PanelVector3(-0.5, -0.5, 0)
pnt2 = paraBEM.PanelVector3(0.5, -0.5, 0)
pnt3 = paraBEM.PanelVector3(0.5, 0.5, 0)
pnt4 = paraBEM.PanelVector3(-0.5, 0.5, 0)
source = paraBEM.Panel3([pnt1, pnt2, pnt3, pnt4])
x = np.linspace(-0, 5, 500)
y = []
for xi in x:
target = paraBEM.PanelVector3(xi, 0., 0.1)
panel_infl = doublet_3_0_vsaero(target, source)
point_infl = doublet_3_0_n0(target, source)
y.append([panel_infl, point_infl, abs(panel_infl - point_infl)])
y = list(zip(*y))
plt.figure(figsize=(8, 3))
plt.gcf().subplots_adjust(bottom=0.15)
plt.ylabel("Einfluss")
from __future__ import division
import numpy as np
import matplotlib
matplotlib.use('Agg')
from matplotlib import pyplot as plt
import paraBEM
from paraBEM.pan3d import doublet_3_0_sphere, doublet_3_0_n0
x_range = [-1, 0, 1]
y_range = [-1, 0, 1]
points = [paraBEM.PanelVector3(x, y, 0) for y in y_range for x in x_range]
panel_indices = [[0, 1, 4, 3], [1, 2, 5, 4], [3, 4, 7, 6], [4, 5, 8, 7]]
panels = [
paraBEM.Panel3([points[index] for index in indices])
for indices in panel_indices
]
mue = [1, 1, 1, 100]
mue_mid = sum(mue) / 4
mid_pan = paraBEM.Panel3([points[0], points[2], points[8], points[6]])
def infl_near(point):
out = 0
target = paraBEM.Vector3(*point)
for i, pan in enumerate(panels):
out += mue[i] * doublet_3_0_sphere(target, pan)
return out
import paraBEM
from paraBEM.pan3d import doublet_3_0_vsaero, doublet_3_0_vsaero_v, doublet_3_0_sphere
from paraBEM.vtk_export import VtkWriter
import numpy
from paraBEM.utils import check_path
v1 = paraBEM.PanelVector3(-0.5, -0.5, 0)
v2 = paraBEM.PanelVector3(0.5, -0.5, 0)
v3 = paraBEM.PanelVector3(0.5, 0.5, 0)
v4 = paraBEM.PanelVector3(-0.5, 0.5, 0)
p = paraBEM.Panel3([v1, v2, v3, v4])
# p = paraBEM.Panel3([v1, v2, v3]) # triangle
p.potential = 1.
n = 50
a = numpy.linspace(-1, 1, n).tolist()
b = [paraBEM.PanelVector3(i, j, k) for i in a for j in a for k in a]
pot = [doublet_3_0_sphere(i, p) for i in b]
vel = [doublet_3_0_vsaero_v(i, p) for i in b]
writer = VtkWriter()
with open(check_path("results/panel_influence.vtk"), "w") as _file:
writer.structed_grid(_file, "duplet", [n, n, n])
writer.points(_file, b)
writer.data(_file,
pot,
name="potential",
_type="SCALARS",
import numpy as np
import paraBEM
from paraBEM import pan3d
v1 = paraBEM.PanelVector3(-0.5, -0.5, 0)
v2 = paraBEM.PanelVector3(0.5, -0.5, 0)
v3 = paraBEM.PanelVector3(0.5, 0.5, 0)
v4 = paraBEM.PanelVector3(-0.5, 0.5, 0)
p = paraBEM.Panel3([v1, v2, v3, v4])
v5 = paraBEM.Vector3(0.5, 0, 0.5)
v6 = paraBEM.Vector3(0.4999, 0, 0)
v7 = paraBEM.Vector3(0.5, 0.0, 0)
v8 = paraBEM.Vector3(0.5001, 0, 0)
checklist = [v1, v2, v3, v4, v5, v6, v7, v8, p.center]
for v in checklist:
dip, src = pan3d.doublet_src_3_0_vsaero(v, p)
print(v, ": doublet:", dip, "source:", src)
def paraBEM_Panels(glider,
midribs=0,
profile_numpoints=None,
num_average=0,
symmetric=False,
distribution=None):
"""return the vertices, panels and the trailing edge of a glider, as paraBEM objects.
midribs: midribs of a cell spanwise. if num_average is greater then
0 ballooning will be disables
profile_numpoints: coordinates of every rib, choordwise
num_average: steps to average a cell profile
symmetric: set to True if a symmetric result is expected (this will
reduce evaluation time)
"""
# paraBEM is not a dependency of openglider so if problems occure here, get the module.
import paraBEM
if symmetric:
glider = glider.copy()
else:
glider = glider.copy_complete()
glider.close_rib(0)
glider.close_rib()
if profile_numpoints:
glider.profile_x_values = Distribution.from_nose_cos_distribution(
profile_numpoints, 0.2)
if num_average > 0:
glider.apply_mean_ribs(num_average)
glider.close_rib()
ribs = glider.return_ribs(midribs, ballooning=False)
else:
ribs = glider.return_ribs(midribs)
# deleting the last vertex of every rib (no trailing edge gap)
ribs = [rib[:-1] for rib in ribs]
# get a numbered representation + flatten vertices
i = 0
vertices = []
ribs_new = []
panels = []
sym_panels = []
trailing_edge = []
for rib in ribs:
rib_new = []
for vertex in rib:
rib_new.append(i)
vertices.append(vertex)
i += 1
rib_new.append(rib_new[0])
ribs_new.append(rib_new)
ribs = ribs_new
panel_nr = 0
for i, rib_i in enumerate(ribs[:-1]):
rib_j = ribs[i + 1]
if symmetric:
if vertices[rib_j[0]][1] > 0.00001:
trailing_edge.append(rib_i[0])
else:
trailing_edge.append(rib_i[0])
if i == len(ribs[:-2]):
trailing_edge.append(rib_j[0])
for k, _ in enumerate(rib_j[:-1]):
l = k + 1
panel = [rib_i[k], rib_j[k], rib_j[l], rib_i[l]]
if symmetric:
sym = True
add_panel = False
for p in panel:
if not vertices[p][
1] > -0.000001: # if one point lies on the y- side
sym = False # y- is the mirrored side
if not vertices[p][
1] < 0.0001: # if one point lies on the y+ side
add_panel = True
if add_panel:
panels.append(panel)
if sym:
sym_panels.append(panel_nr)
panel_nr += 1
else:
panels.append(panel)
vertices = [paraBEM.PanelVector3(*point) for point in vertices]
panels = [
paraBEM.Panel3([vertices[nr] for nr in panel]) for panel in panels
]
trailing_edge = [vertices[nr] for nr in trailing_edge]
for nr in sym_panels:
panels[nr].set_symmetric()
return vertices, panels, trailing_edge
import numpy as np
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import paraBEM
from paraBEM.pan3d import doublet_3_0_sphere as doublet
from paraBEM.utils import check_path
pnt1 = paraBEM.PanelVector3(-0.5, -0.5, 0)
pnt2 = paraBEM.PanelVector3(0.5, -0.5, 0)
pnt3 = paraBEM.PanelVector3(0.5, 0.5, 0)
pnt4 = paraBEM.PanelVector3(-0.5, 0.5, 0)
source = paraBEM.Panel3([pnt1, pnt2, pnt3, pnt4])
x = np.linspace(-4, 4, 100)
y = []
for xi in x:
target1 = paraBEM.PanelVector3(xi, 0., 0.0)
target2 = paraBEM.PanelVector3(xi, 0, 0.5)
target3 = paraBEM.PanelVector3(xi, 0, 1.0)
val1 = doublet(target1, source)
val2 = doublet(target2, source)
val3 = doublet(target3, source)
y.append([val1, val2, val3])
fig = plt.figure()
ax1 = fig.add_subplot(131)
ax1.plot(x, y)
import numpy as np
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import paraBEM
from paraBEM.pan3d import src_3_0_vsaero
from paraBEM.utils import check_path
pnt1 = paraBEM.PanelVector3(-1, -1, 0)
pnt2 = paraBEM.PanelVector3(1, -1, 0)
pnt3 = paraBEM.PanelVector3(1, 1, 0)
pnt4 = paraBEM.PanelVector3(-1, 1, 0)
source = paraBEM.Panel3([pnt1, pnt2, pnt3, pnt4])
fig = plt.figure()
x = np.arange(-4, 4, 0.01)
y = []
for xi in x:
target1 = paraBEM.Vector3(xi, 0, 0.0)
target2 = paraBEM.Vector3(xi, 0, 0.5)
target3 = paraBEM.Vector3(xi, 0, 1)
val1 = src_3_0_vsaero(target1, source)
val2 = src_3_0_vsaero(target2, source)
val3 = src_3_0_vsaero(target3, source)
y.append([val1, val2, val3])
ax1 = fig.add_subplot(131)
ax1.plot(x, y)
import paraBEM
from paraBEM import pan3d
pnt1 = paraBEM.PanelVector3(-0.4, -0.5, 0)
pnt2 = paraBEM.PanelVector3(0.5, -0.2, 0)
pnt3 = paraBEM.PanelVector3(0.3, 0.5, 0)
pnt4 = paraBEM.PanelVector3(-0.5, 0.5, 0)
pnt5 = paraBEM.PanelVector3(0.0, 0, 1)
pnt6 = paraBEM.PanelVector3(0.3, 0.3, 0.3)
source = paraBEM.Panel3([pnt1, pnt2, pnt3, pnt4])
checklist = [pnt1, pnt2, pnt3, pnt4, pnt5, pnt6, source.center]
for trg_pnt in checklist:
dip = pan3d.doublet_3_0_sphere(trg_pnt, source)
print(trg_pnt, ": doublet:", dip)
def rib3d(airfoil, y_pos):
out = [paraBEM.PanelVector3(coo[0], y_pos, coo[1]) for coo in airfoil.coordinates[:-1]]
out.append(out[0])
out[0].wake_vertex = True
return out