Why most aerodynamic tools fail beyond stall – and what flight simulators need instead
Source: Dev.to
Background
Most aerodynamic tools stop working after about 20° angle of attack. For flight simulators and game development, however, it is essential to model the behavior of aircraft during spins, tailslides, and aerobatics, which involve post‑stall and reverse‑flow regimes.
SimiFoil Overview
SimiFoil began as an internal utility for the SimiFlight simulator project and has grown into a lightweight aerodynamic curve generator suitable for flight simulators, RC aircraft, and game engines. It produces continuous, plausible aerodynamic coefficients over the full 360° angle‑of‑attack range. The goal is stability and simulation‑friendliness, not CFD‑level accuracy, making the data ideal for real‑time applications and Blade Element Theory (BET).
Supported Airfoil Types
- Classical and ideal airfoil shapes
- Flat plates with thickness or rounded edges
- Airfoils with blunt or thick trailing edges
- Highly modified or non‑classical geometries
Even for unconventional profiles, the generated curves remain physically plausible and numerically stable—crucial for control‑system simulations.
Validation
The model was compared against experimental wind‑tunnel data, notably NACA Technical Note 3361 (1955, Critzos et al.), which documents the NACA 0012 airfoil from 0° to 180° (and up to 360°). The agreement is remarkably close given the real‑time constraints and analytical nature of the approach.
Web Demo
A browser‑based demo lets you:
- Analyze lift (Cl), drag (Cd), and moment (Cm) coefficients
- Explore polar plots (Cl vs Cd)
- Design airfoils and experiment in a visual wind tunnel
Try the free Web Demo: SimiFoil Web Demo
File export is intentionally disabled in the demo.
Desktop Version
A standalone desktop application provides:
- CSV and LUT export
- Compatibility with XFoil / XFLR5 formats
The desktop version is ready for release and will enable seamless integration into existing analysis tools and simulation workflows.
Ongoing Development
Future work includes:
- Refining the aerodynamic model
- Expanding feature sets based on user feedback and real‑world use cases
Community Feedback
If you work in flight simulation, how do you currently handle post‑stall and reverse‑flow aerodynamics? Your insights are welcome.