"""Demonstrates running Ptera Software's UnsteadyRingVortexLatticeMethodSolver with a
custom flapping-wing airplane."""
# First, import the software's main package. Note that if you wished to import this
# software into another package, you would first install it by running "pip install
# pterasoftware" in your terminal.
import pterasoftware as ps
# Create an Airplane with our custom geometry. I am going to declare every parameter for
# Airplane, even though most of them have usable default values. This is for educational
# purposes, but keep in mind that it makes the code much longer than it needs to be. For
# details about each parameter, read the detailed class docstring. The same caveats
# apply to the other classes, methods, and functions I call in this script.
example_airplane = ps.Airplane(
wings=[
ps.Wing(
wing_cross_sections=[
ps.WingCrossSection(
num_spanwise_panels=8,
chord=1.75,
Lp_Wcsp_Lpp=(0.0, 0.0, 0.0),
angles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
control_surface_symmetry_type="symmetric",
control_surface_hinge_point=0.75,
control_surface_deflection=0.0,
spanwise_spacing="cosine",
airfoil=ps.Airfoil(
name="naca2412",
outline_A_Lp=None,
resample=True,
n_points_per_side=400,
),
),
ps.WingCrossSection(
num_spanwise_panels=None,
chord=1.5,
Lp_Wcsp_Lpp=(0.75, 6.0, 1.0),
angles_Wcsp_to_Wcs_ixyz=(0.0, 5.0, 0.0),
control_surface_symmetry_type="symmetric",
control_surface_hinge_point=0.75,
control_surface_deflection=0.0,
spanwise_spacing=None,
airfoil=ps.Airfoil(
name="naca2412",
outline_A_Lp=None,
resample=True,
n_points_per_side=400,
),
),
],
name="Main Wing",
Ler_Gs_Cgs=(0.0, 0.5, 0.0),
angles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
symmetric=True,
mirror_only=False,
symmetryNormal_G=(0.0, 1.0, 0.0),
symmetryPoint_G_Cg=(0.0, 0.0, 0.0),
num_chordwise_panels=6,
chordwise_spacing="uniform",
),
ps.Wing(
wing_cross_sections=[
ps.WingCrossSection(
num_spanwise_panels=8,
chord=1.5,
Lp_Wcsp_Lpp=(0.0, 0.0, 0.0),
angles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
control_surface_symmetry_type="symmetric",
control_surface_hinge_point=0.75,
control_surface_deflection=0.0,
spanwise_spacing="uniform",
airfoil=ps.Airfoil(
name="naca0012",
outline_A_Lp=None,
resample=True,
n_points_per_side=400,
),
),
ps.WingCrossSection(
num_spanwise_panels=None,
chord=1.0,
Lp_Wcsp_Lpp=(0.5, 2.0, 1.0),
angles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
control_surface_symmetry_type="symmetric",
control_surface_hinge_point=0.75,
control_surface_deflection=0.0,
spanwise_spacing=None,
airfoil=ps.Airfoil(
name="naca0012",
outline_A_Lp=None,
resample=True,
n_points_per_side=400,
),
),
],
name="V-Tail",
Ler_Gs_Cgs=(5.0, 0.0, 0.0),
angles_Gs_to_Wn_ixyz=(0.0, -5.0, 0.0),
symmetric=True,
mirror_only=False,
symmetryNormal_G=(0.0, 1.0, 0.0),
symmetryPoint_G_Cg=(0.0, 0.0, 0.0),
num_chordwise_panels=6,
chordwise_spacing="uniform",
),
],
name="Example Airplane",
Cg_GP1_CgP1=(0.0, 0.0, 0.0),
weight=0.0,
s_ref=None,
c_ref=None,
b_ref=None,
)
# Now define the main Wing's root and tip WingCrossSections' WingCrossSectionMovements.
main_wing_root_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[0].wing_cross_sections[0],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
main_wing_tip_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[0].wing_cross_sections[1],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
# The main Wing was defined to have symmetric=True, mirror_only=False, and with a
# symmetry plane offset non coincident with the Wing's axes yz plane. Therefore, that
# Wing had type 5 symmetry (see the Wing class documentation for more details on
# symmetry types). Therefore, it was actually split into two Wings, with the second Wing
# being a reflected version of the first. Therefore, we need to define a WingMovement
# for this reflected Wing. To start, we'll first define the reflected main Wing's root
# and tip WingCrossSections' WingCrossSectionMovements.
reflected_main_wing_root_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[1].wing_cross_sections[0],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
reflected_main_wing_tip_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[1].wing_cross_sections[1],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
# Now define the V-tail's root and tip WingCrossSections' WingCrossSectionMovements.
v_tail_root_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[2].wing_cross_sections[0],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
v_tail_tip_wing_cross_section_movement = ps.WingCrossSectionMovement(
base_wing_cross_section=example_airplane.wings[2].wing_cross_sections[1],
ampLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
periodLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
spacingLp_Wcsp_Lpp=("sine", "sine", "sine"),
phaseLp_Wcsp_Lpp=(0.0, 0.0, 0.0),
ampAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
periodAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Wcsp_to_Wcs_ixyz=("sine", "sine", "sine"),
phaseAngles_Wcsp_to_Wcs_ixyz=(0.0, 0.0, 0.0),
)
# Now define the main Wing's WingMovement, the reflected main Wing's WingMovement and
# the V-tail's WingMovement.
main_wing_movement = ps.WingMovement(
base_wing=example_airplane.wings[0],
wing_cross_section_movements=[
main_wing_root_wing_cross_section_movement,
main_wing_tip_wing_cross_section_movement,
],
ampLer_Gs_Cgs=(0.0, 0.0, 0.0),
periodLer_Gs_Cgs=(0.0, 0.0, 0.0),
spacingLer_Gs_Cgs=("sine", "sine", "sine"),
phaseLer_Gs_Cgs=(0.0, 0.0, 0.0),
ampAngles_Gs_to_Wn_ixyz=(15.0, 0.0, 0.0), # (0.0, 0.0, 0.0),
periodAngles_Gs_to_Wn_ixyz=(1.0, 0.0, 0.0), # (0.0, 0.0, 0.0),
spacingAngles_Gs_to_Wn_ixyz=("sine", "sine", "sine"),
phaseAngles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
)
reflected_main_wing_movement = ps.WingMovement(
base_wing=example_airplane.wings[1],
wing_cross_section_movements=[
reflected_main_wing_root_wing_cross_section_movement,
reflected_main_wing_tip_wing_cross_section_movement,
],
ampLer_Gs_Cgs=(0.0, 0.0, 0.0),
periodLer_Gs_Cgs=(0.0, 0.0, 0.0),
spacingLer_Gs_Cgs=("sine", "sine", "sine"),
phaseLer_Gs_Cgs=(0.0, 0.0, 0.0),
ampAngles_Gs_to_Wn_ixyz=(15.0, 0.0, 0.0), # (0.0, 0.0, 0.0),
periodAngles_Gs_to_Wn_ixyz=(1.0, 0.0, 0.0), # (0.0, 0.0, 0.0),
spacingAngles_Gs_to_Wn_ixyz=("sine", "sine", "sine"),
phaseAngles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
)
v_tail_movement = ps.WingMovement(
base_wing=example_airplane.wings[2],
wing_cross_section_movements=[
v_tail_root_wing_cross_section_movement,
v_tail_tip_wing_cross_section_movement,
],
ampLer_Gs_Cgs=(0.0, 0.0, 0.0),
periodLer_Gs_Cgs=(0.0, 0.0, 0.0),
spacingLer_Gs_Cgs=("sine", "sine", "sine"),
phaseLer_Gs_Cgs=(0.0, 0.0, 0.0),
ampAngles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
periodAngles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
spacingAngles_Gs_to_Wn_ixyz=("sine", "sine", "sine"),
phaseAngles_Gs_to_Wn_ixyz=(0.0, 0.0, 0.0),
)
# Delete the extraneous pointers to the WingCrossSectionMovements, as these are now
# contained within the WingMovements. This is optional, but it can make debugging
# easier.
del main_wing_root_wing_cross_section_movement
del main_wing_tip_wing_cross_section_movement
del reflected_main_wing_root_wing_cross_section_movement
del reflected_main_wing_tip_wing_cross_section_movement
del v_tail_root_wing_cross_section_movement
del v_tail_tip_wing_cross_section_movement
# Now define the example Airplane's AirplaneMovement.
airplane_movement = ps.AirplaneMovement(
base_airplane=example_airplane,
wing_movements=[main_wing_movement, reflected_main_wing_movement, v_tail_movement],
ampCg_GP1_CgP1=(0.0, 0.0, 0.0),
periodCg_GP1_CgP1=(0.0, 0.0, 0.0),
spacingCg_GP1_CgP1=("sine", "sine", "sine"),
phaseCg_GP1_CgP1=(0.0, 0.0, 0.0),
)
# Delete the extraneous pointers to the WingMovements.
del main_wing_movement
del reflected_main_wing_movement
del v_tail_movement
# Define a new OperatingPoint.
example_operating_point = ps.OperatingPoint(
rho=1.225, vCg__E=10.0, alpha=1.0, beta=0.0, externalFX_W=0.0, nu=15.06e-6
)
# Define the OperatingPoint's OperatingPointMovement.
operating_point_movement = ps.OperatingPointMovement(
base_operating_point=example_operating_point, periodVCg__E=0.0, spacingVCg__E="sine"
)
# Delete the extraneous pointer.
del example_operating_point
# Define the Movement. This contains the AirplaneMovement and the
# OperatingPointMovement.
movement = ps.Movement(
airplane_movements=[airplane_movement],
operating_point_movement=operating_point_movement,
delta_time=None,
num_cycles=3,
num_chords=None,
num_steps=None,
)
# Delete the extraneous pointers.
del airplane_movement
del operating_point_movement
# Define the UnsteadyProblem.
example_problem = ps.UnsteadyProblem(
movement=movement,
)
# Define a new solver. The available solver classes are
# SteadyHorseshoeVortexLatticeMethodSolver, SteadyRingVortexLatticeMethodSolver, and
# UnsteadyRingVortexLatticeMethodSolver. We'll create an
# UnsteadyRingVortexLatticeMethodSolver, which requires a UnsteadyProblem.
example_solver = ps.UnsteadyRingVortexLatticeMethodSolver(
unsteady_problem=example_problem,
)
# Delete the extraneous pointer.
del example_problem
# Run the solver.
example_solver.run(
prescribed_wake=True,
show_progress=True,
)
print("The simulation has finished.")
# Save the solved solver to a .psz file. This allows us to load the results later
# without re-running the simulation.
print("Saving the solver...")
ps.save("example_solver.psz", example_solver)
print("Finished saving the solver.")
# Load the saved solver. The loaded object is identical to the original and can be
# passed to any output function.
print("Loading the saved solver...")
loaded_solver = ps.load("example_solver.psz")
# The load function is annotated as returning object because a saved file can hold any
# Ptera Software object. This assert narrows the type for type checkers and guards
# against loading the wrong file.
assert isinstance(
loaded_solver,
ps.UnsteadyRingVortexLatticeMethodSolver,
)
print("Finished loading the saved solver.")
# Call the animate function on the loaded solver. This produces an animated WebP of the
# wake being shed, saved in the same directory as this script. Press any key, after
# orienting the view, to begin the animation.
#
# The speed parameter plays the saved animation back at a fraction of real time. Half
# speed makes it easier to follow a single flap and see where the vortices are shed,
# since at true speed each stroke of this airplane's one second flapping cycle passes
# quickly. Slowing it further would make the playback choppy, because a slower speed
# holds each frame on screen longer rather than adding frames.
ps.animate(
loaded_solver,
scalar_type="lift",
show_wake_vortices=True,
save=True,
speed=0.5,
)
