Example/busbar joule heating

.gitignore

@@ -114,3 +114,4 @@ venv.bak/
 
 # Generated example
 src/ansys/pyaedt/examples/simple_example.py
+.vscode/

examples/low_frequency/magnetic/busbar_joule_heating.py

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+# # Busbar Joule Heating Analysis with Maxwell 3D
+#
+# Copyright (C) 2023 - 2025 ANSYS, Inc. and/or its affiliates.
+# SPDX-License-Identifier: MIT
+#
+# ## Overview
+#
+# This example demonstrates how to set up and solve a busbar Joule heating analysis using Maxwell 3D and PyAEDT. We will learn the complete workflow including:
+#
+# - Geometry creation and material assignment
+# - Current excitation setup following Kirchhoff's laws
+# - Mesh configuration for AC analysis
+# - Eddy current analysis execution
+# - Post-processing for field visualization
+# - Engineering metrics extraction
+#
+# ## Core Concepts and Principles
+#
+# **Busbar Joule heating analysis** is critical in power electronics and electrical distribution systems.
+# At AC frequencies, the **skin effect** causes non-uniform current distribution, which increases
+# resistance and power losses.
+#
+# Maxwell 3D's eddy current solver captures these frequency-dependent phenomena, enabling accurate prediction of:
+# - Power losses and current density distributions
+# - Thermal loads for thermal management
+# - AC resistance vs DC resistance
+# - Skin depth effects on current distribution
+#
+# This example demonstrates the complete electromagnetic analysis workflow for conductor systems.
+#
+# Keywords: **Maxwell 3D**, **Eddy Current**, **Joule Heating**, **Skin Effect**
+
+# ## Prerequisites
+#
+# ### Perform imports
+
+# +
+import math
+import os
+import tempfile
+import time
+
+from ansys.aedt.core import Maxwell3d
+# -
+
+# ### Define constants
+# Define geometric dimensions and electrical parameters for the busbar system.
+
+AEDT_VERSION = "2025.2"
+NG_MODE = False
+PROJECT_NAME = "Busbar_JouleHeating_Simple.aedt"
+
+# Geometry parameters (mm)
+BUSBAR_L = 100.0
+BUSBAR_W = 10.0
+BUSBAR_H = 5.0
+TAB_L = 5.0
+TAB_W = 3.0
+TAB_H = 3.0
+
+# Electrical parameters
+I1 = 100.0  # Input current 1 (A)
+I2 = 100.0  # Input current 2 (A)
+FREQ = 50  # Frequency (Hz)
+
+print("Maxwell 3D Busbar Joule Heating Analysis")
+print(f"Busbar dimensions: {BUSBAR_L} x {BUSBAR_W} x {BUSBAR_H} mm")
+print(f"Input currents: {I1}A + {I2}A = {I1+I2}A total")
+print(f"Frequency: {FREQ} Hz")
+
+# ### Create temporary directory
+#
+# Create a temporary working directory.
+# The name of the working folder is stored in ``temp_folder.name``.
+#
+# > **Note:** The final cell in the notebook cleans up the temporary folder. If you want to
+# > retrieve the AEDT project and data, do so before executing the final cell in the notebook.
+
+temp_folder = tempfile.TemporaryDirectory(suffix=".ansys")
+project_path = os.path.join(temp_folder.name, PROJECT_NAME)
+
+# ### Launch application
+#
+# Start Maxwell 3D with eddy current solution type and set model units.
+
+m3d = Maxwell3d(
+    project=project_path,
+    version=AEDT_VERSION,
+    design="Busbar_JouleHeating",
+    solution_type="Eddy Current",
+    new_desktop=True,
+    non_graphical=NG_MODE,
+)
+m3d.modeler.model_units = "mm"
+print("Maxwell 3D initialized")
+
+# ## Model Preparation
+#
+# Create the main busbar conductor and terminal tabs, then unite them into a single object.
+
+# ### Create 3D model
+#
+print("\nCreating Geometry")
+
+# Main busbar
+busbar = m3d.modeler.create_box(
+    origin=[0, 0, 0], sizes=[BUSBAR_L, BUSBAR_W, BUSBAR_H], name="MainBusbar"
+)
+m3d.assign_material(busbar, "copper")
+
+# Input tabs
+input_tab1 = m3d.modeler.create_box(
+    origin=[-TAB_L, 1.0, 0.0], sizes=[TAB_L, TAB_W, BUSBAR_H], name="InputTab1"
+)
+m3d.assign_material(input_tab1, "copper")
+
+input_tab2 = m3d.modeler.create_box(
+    origin=[-TAB_L, 6.0, 0.0], sizes=[TAB_L, TAB_W, BUSBAR_H], name="InputTab2"
+)
+m3d.assign_material(input_tab2, "copper")
+
+# Output tab
+output_tab = m3d.modeler.create_box(
+    origin=[BUSBAR_L, 3.0, 0.0], sizes=[TAB_L, 4.0, BUSBAR_H], name="OutputTab"
+)
+m3d.assign_material(output_tab, "copper")
+
+# Unite all parts
+united = m3d.modeler.unite([busbar, input_tab1, input_tab2, output_tab])
+conductor = m3d.modeler[united] if isinstance(united, str) else united
+conductor.name = "CompleteBusbar"
+print(f"Created united conductor with {len(conductor.faces)} faces")
+
+# ### Assign boundary conditions
+#
+# Select terminal faces and assign current excitations following Kirchhoff's current law.
+
+# +
+print("\nSelecting Terminal Faces")
+
+# Sort faces by x-coordinate to identify input and output terminals
+faces_sorted = sorted(conductor.faces, key=lambda f: f.center[0])
+left_x = faces_sorted[0].center[0]
+right_x = faces_sorted[-1].center[0]
+
+# Get faces at left and right ends
+left_faces = [f for f in faces_sorted if abs(f.center[0] - left_x) < 1e-3]
+right_faces = [f for f in faces_sorted if abs(f.center[0] - right_x) < 1e-3]
+
+# Select terminal faces
+input_face1 = left_faces[0].id
+input_face2 = left_faces[1].id if len(left_faces) > 1 else left_faces[0].id
+output_face = right_faces[0].id
+
+print(f"Selected input faces: {input_face1}, {input_face2}")
+print(f"Selected output face: {output_face}")
+
+print("\nAssigning Current Excitations")
+
+# Assign current excitations (following Kirchhoff's current law)
+current1 = m3d.assign_current(
+    assignment=input_face1, amplitude=I1, phase=0, name="InputCurrent1"
+)
+
+current2 = m3d.assign_current(
+    assignment=input_face2, amplitude=I2, phase=0, name="InputCurrent2"
+)
+
+current3 = m3d.assign_current(
+    assignment=output_face, amplitude=-(I1 + I2), phase=0, name="OutputCurrent"
+)
+
+print(f"Input Current 1: {I1}A")
+print(f"Input Current 2: {I2}A")
+print(f"Output Current: {-(I1 + I2)}A")
+print(f"Current balance: {I1 + I2 + (-(I1 + I2))} = 0A")
+
+print("\nCreating Air Region")
+
+air = m3d.modeler.create_air_region(
+    x_pos=0, y_pos=50, z_pos=100, x_neg=0, y_neg=50, z_neg=100
+)
+print("Air region created with 50% padding")
+# -
+
+# ### Define solution setup
+#
+# Set up the eddy current analysis with frequency, convergence criteria, and mesh settings.
+
+# +
+print("\n Setting Up Analysis ")
+
+setup = m3d.create_setup("EddyCurrentSetup")
+setup.props["Frequency"] = f"{FREQ}Hz"
+setup.props["PercentError"] = 2
+setup.props["MaximumPasses"] = 8
+setup.props["MinimumPasses"] = 2
+setup.props["PercentRefinement"] = 30
+
+print(f"Analysis setup created for {FREQ} Hz")
+
+mesh = m3d.mesh.assign_length_mesh(
+    assignment=conductor.name,
+    maximum_length=3.0,  # 3mm elements for skin effect resolution
+    name="ConductorMesh",
+)
+print("Mesh operation assigned")
+# -
+
+# ### Run analysis
+#
+# Execute the finite element solver with automatic adaptive mesh refinement.
+
+print("\n Running Analysis ")
+print("Starting solver... (this may take a few minutes)")
+
+validation = m3d.validate_simple()
+print(f"Design validation: {'PASSED' if validation else 'WARNING'}")
+
+# Solve
+m3d.analyze_setup(setup.name)
+print("Analysis completed")
+
+# ## Postprocess
+#
+# Get Ohmic loss (Joule heating) results from the electromagnetic field solution.
+
+# ### Evaluate loss
+#
+# +
+print("\n--- Extracting Results ---")
+
+setup_sweep = f"{setup.name} : LastAdaptive"
+
+quantities_ec = m3d.post.available_report_quantities(report_category="EddyCurrent")
+print(f"Available quantities: {quantities_ec}")
+
+solution_data = m3d.post.get_solution_data(
+    expressions=["SolidLoss"],
+    report_category="EddyCurrent",
+    setup_sweep_name=setup_sweep,
+)
+
+total_loss = solution_data.data_magnitude()[0]
+print(f"\nOhmic Loss (Joule heating): {total_loss:.6f} W")
+# -
+
+# ### Visualize fields
+#
+# Generate 3D field plots showing current density, electric field, and power loss distributions.
+
+# +
+print("\n Creating Field Plots ")
+
+j_plot = m3d.post.create_fieldplot_surface(
+    assignment=conductor.name, quantity="Mag_J", plot_name="Current_Density_Magnitude"
+)
+print("Current density magnitude plot created")
+
+e_plot = m3d.post.create_fieldplot_surface(
+    assignment=conductor.name, quantity="Mag_E", plot_name="Electric_Field_Magnitude"
+)
+print("Electric field magnitude plot created")
+
+joule_plot = m3d.post.create_fieldplot_volume(
+    assignment=conductor.name,
+    quantity="Ohmic_Loss",
+    plot_name="Joule_Heating_Distribution",
+)
+print("Joule heating distribution plot created")
+
+# Calculate engineering metrics
+# Compute key parameters including resistance, loss density, skin depth, and current density.
+
+print("\nANALYSIS RESULTS")
+
+# Basic electrical parameters
+total_current = I1 + I2
+busbar_volume = BUSBAR_L * BUSBAR_W * BUSBAR_H
+
+# Ohmic Loss
+print(f"Ohmic Loss (Joule heating): {total_loss:.6f} W")
+
+# Loss density
+loss_density = total_loss / busbar_volume
+print(f"Loss density: {loss_density:.8f} W/mm³")
+
+# Equivalent DC resistance
+resistance = total_loss / (total_current**2)
+resistance_micro = resistance * 1e6
+print(f"Equivalent DC resistance: {resistance_micro:.2f} µΩ")
+
+# Skin depth calculation
+mu0 = 4 * math.pi * 1e-7
+sigma_cu = 5.8e7
+omega = 2 * math.pi * FREQ
+skin_depth_m = math.sqrt(2 / (omega * mu0 * sigma_cu))
+skin_depth_mm = skin_depth_m * 1000
+print(f"Skin depth at {FREQ} Hz: {skin_depth_mm:.3f} mm")
+
+current_density = total_current / (BUSBAR_W * BUSBAR_H)
+print(f"Average current density: {current_density:.2f} A/mm²")
+
+power_per_amp_squared = total_loss / (total_current**2)
+print(f"Power per A²: {power_per_amp_squared*1e6:.2f} µW/A²")
+
+# Comparison with conductor thickness
+if BUSBAR_H < 2 * skin_depth_mm:
+    print(
+        f"Note: Busbar thickness ({BUSBAR_H}mm) < 2×skin depth ({2*skin_depth_mm:.1f}mm)"
+    )
+    print(f"      Skin effect is significant - current distribution is non-uniform")
+else:
+    print(
+        f"Note: Busbar thickness ({BUSBAR_H}mm) > 2×skin depth ({2*skin_depth_mm:.1f}mm)"
+    )
+    print(f"      Current flows mainly near surfaces due to skin effect")
+
+print("\n--- Field Plot Information ---")
+print("Current density magnitude (|J|): Shows current distribution")
+print("Electric field magnitude (|E|): Shows electric field intensity")
+print("Joule heating distribution: Shows power loss density")
+# -
+
+# ## Finish
+#
+# ### Save the project
+
+print(f"\n--- Saving Project ---")
+m3d.save_project(project_path)
+print(f"Project saved to: {project_path}")
+
+m3d.release_desktop(close_projects=True, close_desktop=True)
+# Wait 3 seconds to allow AEDT to shut down before cleaning the temporary directory.
+time.sleep(3)
+
+# ### 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()
+
+# ## Conclusion
+# This example demonstrated the complete workflow for busbar Joule heating analysis using Maxwell 3D
+# and PyAEDT. The analysis captured frequency-dependent phenomena including skin effect, current
+# redistribution, and AC losses. Key outputs included power loss calculations, field visualizations,
+# and technical metrics essential for thermal management and design optimization.
+# The example demonstrates:
+# Eddy current distribution in a busbar at AC frequency
+# Joule heating due to AC resistance and skin effect
+# Non-uniform current density due to skin effect
+# Relationship between frequency, skin depth, and power loss