Verwendung
- Installationsbefehl kopieren und das Quellpaket vor der Installation in der eigenen Agentenumgebung prüfen.
- Benötigte Werkzeuge, Zugangsdaten und Hosts im Original prüfen.
- Eingabe und gewünschtes Ergebnis beschreiben und die Ausgabe mit den Quellen abgleichen.
npx skills add https://github.com/soljourner/claude-engineering-skills --skill ansys-simulationVor dem Start
- Die Installation umfasst weder Modellabo noch API-Kontingent oder Dateizugriffsrechte.
- Sterne und Installationen zeigen Aktivität, keine unabhängige Qualitäts- oder Sicherheitsprüfung.
Originales Skill-Dokument
Aus dem Quell-Repository gerendert; Überschriften, Beispiele, Code, Tabellen, Links und Bilder bleiben erhalten.
ANSYS Simulation Integration
Comprehensive guide for automating ANSYS Fluent CFD (Computational Fluid Dynamics) simulations using Python scripting, journal files, and the PyAnsys ecosystem.
Overview
ANSYS Fluent is a leading commercial CFD solver used for simulating fluid flow, heat transfer, and related phenomena in complex geometries. This skill covers automation approaches for:
- ANSYS Workbench: Unified platform for CAD integration, meshing, and workflow management
- ANSYS Fluent: Advanced CFD solver with extensive physics models
- PyAnsys: Python API ecosystem for programmatic control
- Journal Files: Text-based scripting for batch operations
ANSYS Workbench and Fluent Architecture
ANSYS Workbench
- Project-based workflow environment
- Integrates multiple ANSYS tools (Fluent, CFX, Mechanical, etc.)
- Supports parametric studies and design optimization
- Provides geometry and meshing tools (DesignModeler, SpaceClaim, Meshing)
ANSYS Fluent
- Finite volume-based CFD solver
- Extensive turbulence models (k-epsilon, k-omega SST, LES, DES)
- Multiphase flow capabilities
- Heat transfer and combustion modeling
- User-defined functions (UDFs) in C
- Text User Interface (TUI) for scripting
Licensing Requirements
Commercial Licensing
ANSYS products require commercial licenses managed through the ANSYS License Manager:
- Fluent License Types:
- HPC licenses for parallel computing
- Solver licenses (increment-based)
- PrepPost licenses for pre/post-processing
- License Server Setup:
bash
# Set license server environment variable
export ANSYSLMD_LICENSE_FILE=1055@license-server.company.com
# Or in Windows
set ANSYSLMD_LICENSE_FILE=1055@license-server.company.com- License Checkout: Licenses are checked out when starting Fluent and returned on exit
- HPC Licensing: Additional licenses required for parallel runs (typically cores/4)
Academic Licensing
- Student/teaching licenses available with limitations
- Typically limited mesh size and solver capabilities
- Separate license file required
Important Notes
- Always verify license availability before batch runs
- Consider license usage in automated workflows
- Use
-tflag to specify number of processors for HPC licensing
PyAnsys - Python API Introduction
PyAnsys provides a Pythonic interface to ANSYS products, enabling:
- Remote or local session management
- Programmatic control of simulation setup
- Data extraction and post-processing
- Integration with Python data science stack
Installation
bash
# Install PyFluent (for Fluent automation)
pip install ansys-fluent-core
# Install other PyAnsys packages as needed
pip install ansys-mapdl-core # For Mechanical
pip install ansys-dpf-core # For post-processing
pip install ansys-geometry # For geometry operationsBasic PyFluent Usage
python
from ansys.fluent.core import launch_fluent
# Launch Fluent session
session = launch_fluent(precision='double', processor_count=4, mode='solver')
# Access TUI commands
session.tui.file.read_case('case_file.cas')
# Execute commands
session.tui.solve.iterate(100)
# Clean exit
session.exit()Key PyAnsys Components
- ansys-fluent-core: Main Fluent automation package
- ansys-fluent-visualization: Post-processing and visualization
- ansys-geometry: CAD operations and geometry manipulation
- ansys-meshing: Automated meshing workflows
Journal File Scripting
Journal files are text-based scripts containing TUI commands executed sequentially by Fluent.
Journal File Format
scheme
; Comments start with semicolon
; Commands follow TUI menu structure
/file/read-case case_file.cas
/solve/initialize/initialize-flow
/solve/iterate 1000
/file/write-data result.dat
/exit yesRunning Journal Files
bash
# Run Fluent in batch mode with journal file
fluent 3ddp -g -i journal.jou > fluent.log
# Flags:
# 3ddp: 3D double precision
# -g: Run without GUI
# -i: Input journal file
# -t4: Use 4 processorsJournal File Best Practices
- Use absolute paths for file I/O
- Include error checking where possible
- Add comments for maintainability
- Test interactively before batch execution
- Redirect output to log files for debugging
Common Workflow
1. Geometry Import
Via PyFluent:
python
from ansys.fluent.core import launch_fluent
solver = launch_fluent(precision='double', processor_count=4)
# Import geometry
solver.tui.file.import_.cad_geometry(
'geometry.scdoc',
'yes' # Confirm import
)Via Journal File:
scheme
/file/import/cad-geometry geometry.step yes2. Meshing Setup
Mesh Generation Strategy:
- Surface mesh extraction from CAD
- Volume mesh generation (tetrahedral, hex, poly)
- Boundary layer refinement for wall-bounded flows
- Mesh quality checks
PyFluent Meshing:
python
from ansys.fluent.core import launch_fluent
meshing = launch_fluent(precision='double', processor_count=4, mode='meshing')
# Import geometry
meshing.workflow.InitializeWorkflow(WorkflowType='Watertight Geometry')
# Set meshing parameters
meshing.meshing.GlobalSettings.set_state({
'MaxSize': 0.1,
'MinSize': 0.001,
'GrowthRate': 1.2
})
# Generate mesh
meshing.meshing.GenerateMesh()
# Switch to solver
solver = meshing.switch_to_solver()Journal File Meshing:
scheme
/mesh/scale 0.001 0.001 0.001
/mesh/check
/mesh/repair-improve/repair3. Physics Setup
Turbulence Models:
- k-epsilon: General purpose, wall functions
- k-omega SST: Better for adverse pressure gradients, boundary layers
- LES/DES: Large eddy simulation for transient, high-fidelity
Material Properties:
- Fluid properties (density, viscosity, thermal conductivity)
- Solid properties for conjugate heat transfer
PyFluent Physics Setup:
python
# Enable energy equation
solver.tui.define.models.energy('yes')
# Set turbulence model (k-omega SST)
solver.tui.define.models.viscous.kw_sst('yes')
# Define material properties
solver.tui.define.materials.change_create(
'water-liquid',
'water',
'yes',
'constant',
998.2, # Density
'yes',
'constant',
0.001003 # Viscosity
)
# Assign material to cell zone
solver.tui.define.boundary_conditions.fluid(
'fluid-zone',
'yes',
'water',
'no',
'no',
'no',
'no',
0,
'no',
0,
'no',
0,
'no',
'no'
)Journal File Physics:
scheme
/define/models/energy yes no no no no
/define/models/viscous kw-sst yes
/define/materials/change-create air air yes constant 1.225 yes constant 1.7894e-054. Boundary Conditions
Common BC Types:
- Velocity inlet
- Pressure outlet
- Wall (stationary, moving, rotating)
- Symmetry
- Periodic
PyFluent BC Setup:
python
# Velocity inlet
solver.tui.define.boundary_conditions.velocity_inlet(
'inlet',
'yes',
'no',
'yes',
'yes',
'no',
10, # Velocity magnitude (m/s)
'no',
0,
'no',
0,
'no',
300, # Temperature
'no'
)
# Pressure outlet
solver.tui.define.boundary_conditions.pressure_outlet(
'outlet',
'yes',
'no',
0, # Gauge pressure
'no',
300,
'no',
'yes'
)
# Wall with no-slip
solver.tui.define.boundary_conditions.wall(
'wall',
'yes',
'no',
'no',
0,
'no',
0,
'no',
'yes',
'no',
0
)5. Solver Settings
Solution Methods:
- Pressure-velocity coupling (SIMPLE, SIMPLEC, PISO, Coupled)
- Discretization schemes (first-order, second-order upwind, QUICK)
- Gradient evaluation (least squares, Green-Gauss)
PyFluent Solver Configuration:
python
# Set pressure-velocity coupling
solver.tui.solve.set.p_v_coupling(24) # 24 = Coupled
# Set discretization schemes
solver.tui.solve.set.discretization_scheme.pressure(12) # Second order
solver.tui.solve.set.discretization_scheme.mom(1) # Second order upwind
solver.tui.solve.set.discretization_scheme.k(1)
solver.tui.solve.set.discretization_scheme.omega(1)
# Set under-relaxation factors
solver.tui.solve.set.under_relaxation.pressure(0.3)
solver.tui.solve.set.under_relaxation.mom(0.7)
# Initialize flow field
solver.tui.solve.initialize.initialize_flow()
# Run iterations
solver.tui.solve.iterate(1000)Convergence Criteria:
python
# Set residual convergence criteria
solver.tui.solve.monitors.residual.convergence_criteria(
'1e-6', # continuity
'1e-6', # x-velocity
'1e-6', # y-velocity
'1e-6', # z-velocity
'1e-6', # energy
'1e-6', # k
'1e-6' # omega
)6. Post-Processing
Data Extraction:
python
# Create surface for reporting
solver.tui.surface.iso_surface(
'pressure',
'iso-surface-1',
'fluid-zone',
'()',
101325
)
# Export data
solver.tui.file.export.ascii(
'surface-data.csv',
'iso-surface-1',
'()',
'yes',
'pressure',
'velocity-magnitude',
'()'
)
# Calculate force on wall
solver.tui.report.forces.wall_forces(
'yes',
'wall-zone',
'()',
'yes',
'no',
'yes'
)Visualization:
python
# Generate contour plot (requires GUI mode or visualization package)
solver.tui.display.set.contours.filled_contours('yes')
solver.tui.display.contour(
'pressure',
'pressure',
0,
0,
'surface-1',
'()'
)
# Save image
solver.tui.display.save_picture('pressure_contour.png')Batch Mode Execution
Linux/Unix Batch Execution
bash
#!/bin/bash
# batch_fluent.sh
# Set license server
export ANSYSLMD_LICENSE_FILE=1055@license-server.com
# Set number of processors
NPROCS=8
# Run Fluent in batch mode
fluent 3ddp -g -t${NPROCS} -i simulation.jou > fluent_${NPROCS}cores.log 2>&1
# Check exit status
if [ $? -eq 0 ]; then
echo "Simulation completed successfully"
else
echo "Simulation failed - check log file"
exit 1
fiWindows Batch Execution
batch
@echo off
REM batch_fluent.bat
set ANSYSLMD_LICENSE_FILE=1055@license-server.com
set NPROCS=8
"C:\Program Files\ANSYS Inc\v241\fluent\ntbin\win64\fluent.exe" 3ddp -g -t%NPROCS% -i simulation.jou > fluent.log 2>&1
if %ERRORLEVEL% EQU 0 (
echo Simulation completed successfully
) else (
echo Simulation failed - check log file
exit /b 1
)Python-Based Batch Execution
python
import subprocess
import os
from pathlib import Path
def run_fluent_batch(journal_file, num_procs=4, log_file='fluent.log'):
"""
Run Fluent in batch mode with journal file.
Args:
journal_file: Path to journal file
num_procs: Number of processors
log_file: Output log file name
Returns:
bool: True if successful, False otherwise
"""
# Set license server
os.environ['ANSYSLMD_LICENSE_FILE'] = '1055@license-server.com'
# Build command
cmd = [
'fluent',
'3ddp', # 3D double precision
'-g', # No GUI
f'-t{num_procs}', # Number of processors
'-i', journal_file
]
# Run simulation
with open(log_file, 'w') as log:
result = subprocess.run(
cmd,
stdout=log,
stderr=subprocess.STDOUT,
text=True
)
return result.returncode == 0
# Example usage
if __name__ == '__main__':
success = run_fluent_batch(
journal_file='simulation.jou',
num_procs=8,
log_file='fluent_run.log'
)
if success:
print("Simulation completed successfully")
else:
print("Simulation failed - check log file")Parametric Studies
python
import numpy as np
from ansys.fluent.core import launch_fluent
def parametric_study(velocities, case_file):
"""
Run parametric study varying inlet velocity.
Args:
velocities: List of inlet velocities to test
case_file: Base case file
"""
results = {}
for velocity in velocities:
print(f"Running simulation with velocity = {velocity} m/s")
# Launch Fluent
solver = launch_fluent(precision='double', processor_count=4)
# Read base case
solver.tui.file.read_case(case_file)
# Modify inlet velocity
solver.tui.define.boundary_conditions.velocity_inlet(
'inlet',
'yes', 'no', 'yes', 'yes', 'no',
velocity,
'no', 0, 'no', 0, 'no', 300, 'no'
)
# Initialize and solve
solver.tui.solve.initialize.initialize_flow()
solver.tui.solve.iterate(500)
# Extract results
# (Add result extraction here)
# Save case and data
output_file = f'result_v{velocity}.cas.h5'
solver.tui.file.write_case_data(output_file)
solver.exit()
results[velocity] = output_file
return results
# Run parametric study
velocities = np.linspace(5, 25, 5) # 5 to 25 m/s
results = parametric_study(velocities, 'base_case.cas.h5')Best Practices
- License Management: Always check license availability before long batch runs
- Mesh Quality: Verify mesh quality before solving (skewness, aspect ratio)
- Convergence Monitoring: Set appropriate convergence criteria and monitor residuals
- File Management: Use clear naming conventions for parametric studies
- Error Handling: Implement robust error checking in automation scripts
- Documentation: Comment journal files and Python scripts thoroughly
- Version Control: Track journal files and scripts in version control
- Testing: Test automation workflows on small cases before production runs
- Resource Management: Monitor memory and disk usage for large simulations
- Reproducibility: Document all settings for reproducible results
Troubleshooting
Common Issues
- License checkout failures: Check license server connectivity and availability
- Mesh issues: Review mesh quality metrics and refine problematic regions
- Convergence problems: Adjust under-relaxation factors, check BC consistency
- Memory errors: Reduce mesh size or use more nodes in parallel
- File I/O errors: Verify file paths and permissions
Debugging Tips
- Run interactively first to validate workflow
- Check transcript files for TUI command syntax
- Use
-printflag in journal files for debugging - Monitor residual plots for convergence behavior
- Review warning and error messages in log files
Additional Resources
- ANSYS Documentation: Help system within ANSYS products
- PyAnsys Documentation: https://docs.pyansys.com
- ANSYS Learning Hub: Online training and tutorials
- ANSYS Community: User forums and knowledge base
- Fluent User's Guide: Comprehensive theory and usage manual
- Fluent TUI Reference: Complete TUI command listing
