Prepare Thermal-Fluid Simulation Inputs
Use this guide before estimating or submitting a thermal-fluid run. A stable input package makes scenario comparisons reproducible and prevents geometry, units, or boundary changes from being mistaken for an engineering result.
Prerequisites
| Requirement | What to prepare |
|---|---|
| Engineering question | The condition being compared, the decision owner, and the result needed |
| Geometry owner | An approved CAD or USD source with a clear version |
| Operating owner | Reviewed airflow, thermal-load, temperature, and operating assumptions |
| Validation owner | Measurements, reference cases, or acceptance criteria |
| Simulation access | A project or tenant profile that admits the required solver and worker pool |
Input package
Geometry and domain
- Select the room, enclosure, production area, or equipment region that affects the question.
- Include walls, covers, racks, machines, guides, openings, supply faces, and return faces that change the flow.
- Remove decorative detail that adds cells without changing the selected result.
- Resolve open edges, duplicate surfaces, inverted normals, overlapping solids, and unsupported thin features.
- Record the coordinate system, origin, scale, and length unit.
Airflow inputs
Define each inlet or air source with its location, direction, flow rate or velocity, and active area. Define returns and outlets with the intended pressure or flow relationship. Record porous regions, filters, perforated floors, leakage paths, and blocked areas when they affect the scenario.
Thermal inputs
Define heat sources with power, location, active period, and distribution. Record supply temperature, initial temperature, fixed-temperature regions, thermal diffusivity or approved material mapping, and any boundary that adds or removes heat.
Run controls
| Control | Review question |
|---|---|
| Grid or mesh scale | Does it resolve the smallest feature that materially affects the result? |
| Time step and duration | Does the run cover startup, disturbance, or steady behavior? |
| Averaging window | Is the comparison based on the same stable interval? |
| Solver profile | Is the selected profile approved for this project and study type? |
| Output probes | Do slices, lines, points, and regions match the engineering question? |
Procedure
- Create or select the scenario baseline.
- Select the approved CAD or USD resource version.
- Select the matching Model Asset version and component geometry.
- Define the simulation domain and confirm all important openings are represented.
- Enter airflow sources, returns, leakage, porous regions, and initial conditions.
- Enter heat sources, temperatures, and material properties.
- Confirm SI units and coordinate orientation across every source.
- Add probes and result regions needed for comparison.
- Run geometry and input validation.
- Freeze the accepted input versions before submitting the run.
Expected output
The preparation step should produce a versioned input manifest containing:
- scene, CAD, Model Asset, and component versions;
- domain bounds and grid or mesh settings;
- airflow and thermal boundary definitions;
- solver and execution profile;
- baseline identity and scenario parameters;
- checksums, validation findings, and reviewer notes.
Failure handling
| Symptom | Response |
|---|---|
| Cell estimate is unexpectedly high | Remove nonfunctional detail, review domain bounds, and check the minimum feature size |
| Flow enters from the wrong direction | Check face normal, coordinate conversion, and source-vector unit |
| Heat appears in the wrong region | Verify component identity, geometry version, source extent, and power unit |
| Domain leaks or traps flow | Review openings, return faces, overlapping solids, and closed cavities |
| Scenario cannot be frozen | Select resource versions with stable checksums and complete baseline evidence |