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Fields export in transient analysis

This example shows how to leverage PyAEDT to set up a Maxwell 3D transient analysis and then compute the average value of the current density field over a specific coil surface and the magnitude of the current density field over all coil surfaces at each time step of the transient analysis.

Keywords: Maxwell 3D, transient, fields calculator, field export.

Perform imports and define constant

Perform required imports.

import tempfile
import time

import ansys.aedt.core

Define constants.

AEDT_VERSION = "2024.2"
NUM_CORES = 4
NG_MODE = False  # Open AEDT UI when it is launched.

Create temporary directory

Create a temporary directory where downloaded data or dumped data can be stored. If you’d like to retrieve the project data for subsequent use, the temporary folder name is given by temp_folder.name

temp_folder = tempfile.TemporaryDirectory(suffix=".ansys")

Import project

The files required to run this example are downloaded into the temporary working folder.

project_path = ansys.aedt.core.downloads.download_file(
    source="maxwell_transient_fields",
    name="M3D_Transient_StrandedWindings.aedt",
    destination=temp_folder.name,
)

Initialize and launch Maxwell 3D

Initialize and launch Maxwell 3D, providing the version and the path of the project.

m3d = ansys.aedt.core.Maxwell3d(
    project=project_path, version=AEDT_VERSION, non_graphical=NG_MODE
)

PyAEDT INFO: Parsing C:\Users\ansys\AppData\Local\Temp\tmpl2j_wx5q.ansys\maxwell_transient_fields\M3D_Transient_StrandedWindings.aedt.
PyAEDT INFO: Python version 3.10.11 (tags/v3.10.11:7d4cc5a, Apr  5 2023, 00:38:17) [MSC v.1929 64 bit (AMD64)]
PyAEDT INFO: PyAEDT version 0.12.dev0.
PyAEDT INFO: Initializing new Desktop session.
PyAEDT INFO: Log on console is enabled.
PyAEDT INFO: Log on file C:\Users\ansys\AppData\Local\Temp\pyaedt_ansys_484b2bee-f345-402f-b307-831707aeb230.log is enabled.
PyAEDT INFO: Log on AEDT is enabled.
PyAEDT INFO: Debug logger is disabled. PyAEDT methods will not be logged.
PyAEDT INFO: Launching PyAEDT with gRPC plugin.
PyAEDT INFO: New AEDT session is starting on gRPC port 51611
PyAEDT INFO: File C:\Users\ansys\AppData\Local\Temp\tmpl2j_wx5q.ansys\maxwell_transient_fields\M3D_Transient_StrandedWindings.aedt correctly loaded. Elapsed time: 0m 0sec
PyAEDT INFO: AEDT installation Path C:\Program Files\AnsysEM\v242\Win64
PyAEDT INFO: Ansoft.ElectronicsDesktop.2024.2 version started with process ID 4540.
PyAEDT INFO: Project M3D_Transient_StrandedWindings has been opened.
PyAEDT INFO: Active Design set to Maxwell3DDesign2
PyAEDT INFO: Aedt Objects correctly read

Create setup and validate

Create the setup specifying general settings such as StopTime, TimeStep, and SaveFieldsType.

setup = m3d.create_setup(name="Setup1")
setup.props["StopTime"] = "0.02s"
setup.props["TimeStep"] = "0.002s"
setup.props["SaveFieldsType"] = "Every N Steps"
setup.props["N Steps"] = "2"
setup.props["Steps From"] = "0s"
setup.props["Steps To"] = "0.02s"
setup.update()

True

Create field expressions

Create a field expression to evaluate the J field normal to a surface using the advanced fields calculator. The expression is created as a dictionary and then provided as an argument to the add_expression() method.

j_normal = {
    "name": "Jn",
    "description": "J field normal to a surface",
    "design_type": ["Maxwell 3D"],
    "fields_type": ["Fields"],
    "primary_sweep": "Time",
    "assignment": "",
    "assignment_type": [""],
    "operations": [
        "NameOfExpression('<Jx,Jy,Jz>')",
        "Operation('Normal')",
        "Operation('Dot')",
    ],
    "report": ["Field_3D"],
}
m3d.post.fields_calculator.add_expression(j_normal, None)

PyAEDT INFO: Modeler class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: PostProcessor class has been initialized! Elapsed time: 0m 0sec
PyAEDT INFO: Post class has been initialized! Elapsed time: 0m 0sec

'Jn'

Calculate the average value of the J field normal using the advanced fields calculator.

j_avg = {
    "name": "Jn_avg",
    "description": "Average J field normal to a surface",
    "design_type": ["Maxwell 3D"],
    "fields_type": ["Fields"],
    "primary_sweep": "Time",
    "assignment": "Coil_A2_ObjectFromFace1",
    "assignment_type": [""],
    "operations": [
        "NameOfExpression('Jn')",
        "EnterSurface('assignment')",
        "Operation('SurfaceValue')",
        "Operation('Mean')",
    ],
    "report": ["Field_3D"],
}
m3d.post.fields_calculator.add_expression(j_avg, None)

'Jn_avg'

Analyze setup specifying setup name

m3d.analyze_setup(name=setup.name, cores=NUM_CORES)

PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/Maxwell 3D correctly changed.
PyAEDT INFO: Solving design setup Setup1
PyAEDT INFO: Key Desktop/ActiveDSOConfigurations/Maxwell 3D correctly changed.
PyAEDT INFO: Design setup Setup1 solved correctly in 0.0h 0.0m 54.0s

True

Get available report quantities

Get the available report quantities given a specific report category. In this case, Calculator Expressions is the category.

report_types = m3d.post.available_report_types
quantity = m3d.post.available_report_quantities(
    report_category="Fields", quantities_category="Calculator Expressions"
)

Compute time steps of the analysis

Create a fields report object given the nominal sweep. Get the report solution data to compute the time steps of the transient analysis.

sol = m3d.post.reports_by_category.fields(setup=m3d.nominal_sweep)
data = sol.get_solution_data()
time_steps = data.intrinsics["Time"]

PyAEDT INFO: Solution Data Correctly Loaded.

Create field plots over the coil surfaces and export field data

Convert each time step into millimeters. Create field plots over the surface of each coil by specifying the coil object, the quantity to plot, and the time step.

The average value of the J field normal is plotted on the Coil_A2 surface for every time step. The J field is plotted on the surface of each coil for every time-step. Fields data is exported to the temporary folder as an AEDTPLT file.

for time_step in time_steps:
    t = ansys.aedt.core.generic.constants.unit_converter(
        time_step,
        unit_system="Time",
        input_units=data.units_sweeps["Time"],
        output_units="ms",
    )
    m3d.post.create_fieldplot_surface(
        assignment=m3d.modeler.objects_by_name["Coil_A2"],
        quantity=quantity[0],
        plot_name="J_{}_ms".format(t),
        intrinsics={"Time": "{}ms".format(t)},
    )
    mean_j_field_export = m3d.post.export_field_plot(
        plot_name="J_{}_ms".format(t),
        output_dir=temp_folder.name,
        file_format="aedtplt",
    )
    m3d.post.create_fieldplot_surface(
        assignment=[
            o for o in m3d.modeler.solid_objects if o.material_name == "copper"
        ],
        quantity="Mag_J",
        plot_name="Mag_J_Coils_{}_ms".format(t),
        intrinsics={"Time": "{}ms".format(t)},
    )
    mag_j_field_export = m3d.post.export_field_plot(
        plot_name="Mag_J_Coils_{}_ms".format(t),
        output_dir=temp_folder.name,
        file_format="aedtplt",
    )

PyAEDT INFO: Parsing design objects. This operation can take time
PyAEDT INFO: 3D Modeler objects parsed. Elapsed time: 0m 0sec

Release AEDT

m3d.save_project()
m3d.release_desktop()
# Wait 3 seconds to allow AEDT to shut down before cleaning the temporary directory.
time.sleep(3)

PyAEDT INFO: Project M3D_Transient_StrandedWindings Saved correctly
PyAEDT INFO: Desktop has been released and closed.

Clean up

All project files are saved in the folder temp_folder.name. If you’ve run this example as a Jupyter notebook, you can retrieve those project files. The following cell removes all temporary files, including the project folder.

temp_folder.cleanup()

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Download this example

Download this example as a Jupyter Notebook or as a Python script.