Calculate the Net Aerodynamic Forces

Utilize EnSight Net Force Tool in order to Calculate the Net Aerodynamic Forces

Intended to work with EnSight version 24.2 or later

Start an EnSight session

Launch and connect to an instance of EnSight. This example uses a local EnSight installation.

import math

from ansys.pyensight.core import LocalLauncher

session = LocalLauncher().start()

Load a dataset

Load RC Plane case included in the ansys/example-data repository

path = session.download_pyansys_example("RC_Plane", "pyensight", folder=True)
session.load_data(os.path.join(path, "extra300_RC_Plane_cpp.case"))
session.show("image", width=800, height=600)

body_parts = [
    "canopy",
    "fuselage",
    "horizontal_stabilizer",
    "nose",
    "vertical_stabilizer",
    "wing_lower_surface",
    "wing_te",
    "wing_tip",
    "wing_upper_surface",
]

vref = session.ensight.utils.variables.get_const_val("Vinf")
dref = session.ensight.utils.variables.get_const_val("Rho")
aoa = session.ensight.utils.variables.get_const_val("AoA")
session.ensight.utils.variables.get_const_val(session.ensight.objs.core.VARIABLES["AoA"][0])
vxref = vref * math.cos(aoa * math.pi / 180)
vyref = vref * math.sin(aoa * math.pi / 180)
vzref = 0
area_ref = None
session.ensight.utils.variables.calculator.area(["wing_upper_surface"], output_varname="area_ref")
area_ref = session.ensight.utils.variables.get_const_val("area_ref")

if not area_ref:
    raise RuntimeError("The reference area could not be calculated")

Compute forces on 2D parts .. image:: /_static/06_aero_forces_1.png

forces = session.ensight.utils.variables.compute_forces(
    pobj_list=body_parts.copy(),
    press_var_obj="staticPressure",
    shear_var_obj="wallShearStress",
    shear_var_type=session.ensight.utils.variables.SHEAR_VAR_TYPE_STRESS,
    export_filename="test.csv",
    area_ref=area_ref,
    density_ref=dref,
    velocity_x_ref=vxref,
    velocity_y_ref=vyref,
    velocity_z_ref=vzref,
    up_vector=session.ensight.utils.variables.UP_VECTOR_PLUS_Y,
)

# Hide 3D parts and mirror geometry
session.ensight.part.select_begin(1, 5, 7, 8, 9, 10)
session.ensight.part.modify_begin()
session.ensight.part.visible("OFF")
session.ensight.part.modify_end()
session.ensight.part.select_begin(2, 3, 4, 6, 11, 12, 13, 14, 15)
session.ensight.view_transf.fit(0)
session.ensight.part.select_begin(2, 3, 4, 6, 11, 12, 13, 14, 15)
session.ensight.part.modify_begin()
session.ensight.part.symmetry_type("mirror")
session.ensight.part.modify_end()
session.ensight.part.select_begin(2, 3, 4, 6, 11, 12, 13, 14, 15)
session.ensight.part.modify_begin()
session.ensight.part.symmetry_mirror_x("ON")
session.ensight.part.modify_end()
session.ensight.view_transf.fit(0)
session.ensight.view_transf.rotate(16.3245811, 44.9999962, 0)
session.ensight.view.highlight_parts("OFF")

session.show("image", width=800, height=600)

Print out the computed forces

The compute_forces function returns a dictionary that can be easily walked to get all the results

for idx, axis in enumerate(["X", "Y", "Z"]):
    print(f"Per part force {axis}")
    total_pressure_force = 0
    total_shear_force = 0
    for part in body_parts:
        part_press_force = forces["pressure_forces"][part][idx]
        part_shear_force = forces["shear_forces"][part][idx]
        print(f"Pressure {axis} force on {part} surface: {part_press_force}")
        print(f"Shear {axis} force on {part} surface: {part_shear_force}")
        total_pressure_force += part_press_force
        total_shear_force += part_shear_force
    print(f"Total Force along the {axis} direction")
    print(f"Total (Net) Pressure Force {axis} = {total_pressure_force}")
    print(f"Total (Net) Shear Force {axis} = {total_shear_force}")

Thumbnail sphinx_gallery_thumbnail_path = ‘_static/06_aero_forces_1.png’

session.close()