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Spa Examples

Spa-Francorchamps is the first full-track study path in ApexSim. These pages combine practical script usage with theoretical context so model outputs can be interpreted consistently.

Why Spa as tutorial track

  • It contains long straights, high-speed corners, and strong elevation changes.
  • It is complex enough to expose model differences clearly.
  • It is still structured enough for reproducible onboarding studies.

What you should know before starting

  1. Run the Synthetic Track Walkthrough first.
  2. Be familiar with the 6-step workflow from How to Use.
  3. Use default parameters first, then tune one block at a time.

Tutorial sequence

  1. Single-Track Lap
  2. Point-Mass Lap
  3. Model Comparison
  4. Performance Envelope

Common output structure

All Spa scripts write into examples/output/spa/. Subfolders are separated by script purpose (single-track, point-mass, comparison, envelope), so results stay comparable.

Theoretical context used across all Spa pages

  1. Quasi-steady assumption: vehicle states are solved from local equilibrium in arc-length domain, without full transient tire-state dynamics.
  2. Lateral/longitudinal coupling: available \(a_x\) is reduced as required \(a_y\) approaches the lateral limit.
  3. Aero coupling: both drag and downforce scale approximately with \(v^2\), which changes acceleration limits strongly at higher speeds.
  4. Model hierarchy: point-mass is a reduced model; single-track adds yaw and axle-level effects.

Quick run commands

python examples/spa/spa_lap_single_track.py
python examples/spa/spa_lap_point_mass.py
python examples/spa/spa_model_comparison.py
python examples/spa/spa_performance_envelope.py

Neutral analysis checklist

  1. Record physical assumptions and numerical settings for each run.
  2. Compare both global KPIs and local trace behavior along arc length.
  3. Separate model-structure effects from parameter-tuning effects.
  4. State model limitations next to each engineering conclusion.